This changes all variables and functions from using Suspend{ed} to using
Silence{d} as well as documentation, errors and logging.

Some of the work needed to have the backend match user-facing wording.

Ref T661

This puts the verbiage more in line with what the feature does, and
leaves room for other moderation controls in the future.

NOTE: this includes no backend refactoring, which may be confusing. We
should rename things to fit ASAP.

Ref T661

Previously, this had bad template logic and showed the wrong email address.

Ref T695

Ref T695

Also updates some whitespace in the JS.

Ref T695

This also adjusts the style and includes the user's password, so the
admin can easily notify them.

Ref T695

Move logic into template, rather than add another field to the page.

Ref T695

Ref T695

This also includes a bit of explanation about what suspending a user
actually does.

Ref T661

This adds a User.IsSuspended() method and uses it when displaying the
user's status on admin pages, instead of doing a magic number check.
This should also help in the future, in case this logic ever changes.

Ref T661

- update error messages to be correct
- move suspended message into template and include for other pages
- check suspended status on all relevant pages and show message if
logged in user is suspended.
- fix possible nil pointer error
- remove changes to db schema files
- add version comment to migration
- add UserStatus type with UserActive and UserSuspended
- change database table to use status column instead of suspended
- update toggle suspended handler to be toggle status in prep for
possible future inclusion of further user statuses

this adds a new button when viewing a user as an admin, that will
generate and store a new password for the user

This renders all requests for that user's posts, collections and related
ActivityPub endpoints with 404 responses.

While suspended, users may not create or edit posts or collections.

User status is listed in the admin user page

Admin view of user details shows status and now has a button to activate
or suspend a user.

This enables admins on multi-user instances to see all users registered,
and view the details of each, including:

- Username
- Join date
- Total posts
- Last post date
- All blogs
  - Public info
  - Views
  - Total posts
  - Last post date
  - Fediverse followers count

This is the foundation for future user moderation features.

Ref T553