Replace overview when site is with a pending migration

[renatho]

Related to #95379 and #95380

Proposed Changes

• Extract some components from the "Hosting Features" tab, so we can reuse it.
• It customizes the Sites overview with a button to continue the migration when it's pending.
• The button contains a ref as hosting-migration-overview, so we can identify when the user is coming from this page.

This PR Doesn't Include

• Disable other tabs from the menu.
• Update the header when navigating to the site, similar to the changes we have in the listing.

@donnapep, do you think it's fine to deploy it as it is and implement these other parts in other PRs? I think one issue would be fine for both changes. I'll wait for your answer to then create the new issue, otherwise, I'll continue working on this one.

Why are these changes being made?

• We want to offer a way for the users to continue their migration if they stopped in the middle.

Testing Instructions

• If Create pending sticker when loading the "how to migrate" step #95413 wasn't merged yet, merge it into this branch to make tests more real and easier.
• Navigate to the flow /setup/migration.
• Navigate until the "How to migrate" step.
• Navigate to /sites.
• Click on the site, and click on "Start your migration".
• Make sure you navigate back to where you were in the flow.
• Click on the "Do it for me" option.
• Navigate again to the /sites and click on "Start your migration".
• Make sure you navigate back to your choice.
• Return one step and choose the "Do it myself".
• Navigate to the /sites.
• Check that you won't see the button because it changes quickly to the "started" status that will be implemented as part of Post-purchase Migration Experience: Handle selecting a DIFM site in the Sites dashboard that has started migration #95383.
• Now repeat the tests using the flow /setup/hosted-site-migration and make sure it works properly.

Screenshots

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-122283

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-122283&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-122283&env=a8c-for-agencies

[renatho]

Components were extracted so that we could reuse them.

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

App Entrypoints (~210 bytes added 📈 [gzipped])

name           parsed_size           gzip_size
entry-stepper       +499 B  (+0.0%)     +210 B  (+0.0%)
entry-main          +499 B  (+0.0%)     +210 B  (+0.0%)
entry-login         +283 B  (+0.0%)     +132 B  (+0.0%)

Common code that is always downloaded and parsed every time the app is loaded, no matter which route is used.

Sections (~1897 bytes removed 📉 [gzipped])

name                parsed_size           gzip_size
hosting                 +2654 B  (+0.1%)    +1440 B  (+0.3%)
hosting-features         +242 B  (+0.0%)     +193 B  (+0.0%)
site-monitoring          +133 B  (+0.0%)      +39 B  (+0.0%)
site-logs                +133 B  (+0.0%)      +39 B  (+0.0%)
settings                 +133 B  (+0.0%)      +50 B  (+0.0%)
github-deployments       +133 B  (+0.0%)      +46 B  (+0.0%)
staging-site              -61 B  (-0.0%)     +131 B  (+0.0%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Async-loaded Components (~50 bytes added 📈 [gzipped])

name                                       parsed_size           gzip_size
async-load-calypso-layout-command-palette       +133 B  (+0.1%)      +50 B  (+0.1%)

React components that are loaded lazily, when a certain part of UI is displayed for the first time.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[renatho]

@donnapep, do you think it's fine to deploy it as it is and implement these other parts in other PRs? I think one issue would be fine for both changes. I'll wait for your answer to then create the new issue, otherwise, I'll continue working on this one.

I added the "[Status] String Freeze" because we have many new texts, so we'll delay a little to merge this anyway.

[renatho]

This fixes the spacing at the bottom of the tabs.

Without this, it wasn't respecting the padding.

[a8ci18n]

This Pull Request is now available for translation here: https://translate.wordpress.com/deliverables/16927618

Some locales (Hebrew, Japanese) have been temporarily machine-translated due to translator availability. All other translations are usually ready within a few days. Untranslated and machine-translated strings will be sent for translation next Monday and are expected to be completed by the following Friday.

Thank you @renatho for including a screenshot in the description! This is really helpful for our translators.