Rough ES Admin implementation for discussion

[bferguso]

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Description of Change

Adds a management command to manage the Elasticsearch configuration and credentials. Provides the ability create, update, delete and list ES roles, users and API keys.

Issues Solved

#10231

Checklist

• Unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Ticket Background

• Sponsored by:
• Found by: @
• Tested by: @
• Designed by: @ <!-- TBD - in progress ->

Further comments

• This is for discussion, following the principle of least privilege for the ES configuration. Still need to come up with the best way to bootstrap this configuration using superuser credentials.
• Current implementation takes credentials on the command line and also looks for the ES_ADMIN_USER and ES_ADMIN_PASSWORD in settings.
• Can see a need for similar functionality for application Postgres database roles

[bferguso]

@aarongundel, @chiatt - Here's the initial PR for discussion