User preferences/options cleanup - #4615

This is intended to re-organise the various user options and controls, to bring all user-facing controls into a cohesive "my-account" area. This includes the creation of new "my-account" profile controls, so we can target and seperate the editing of "my-account" from that of admin controls which are intended to manage accounts that are not the current user (mostly). Means we can provide a UX intended for the seperate use-cases.

Todo

• Add new my-account profile form.
• Ensure sidebar item highlighting works for all my-account items
• Update "External Auth" fields to always show (not be auth type specific, maybe hidden by default though).
• Have link from user profile to user admin profile form if permissions allow.
• Have link to user public activity profile.
• Update API token URLs and return user to correct location on save/cancel.
• Ensure translations extracted to files
• Provide user self-delete flow
• Clean up & split-out (if needed) old preference test cases.
• Clean up header profile dropdown menu.
• Specifically cover non-admin profile email field disabling/message with testing.
• Test across dark mode.
• Test with different auth methods.
• Re-test each action across all my-account and admin user management views.
• Testing

Docs Updates

• Advise of changes to URLs.
  • No /preferences URLs anymore.
  • API token URLs changed.
  • Old profile routes non-accessible without users-manage permission.

Notes

• Active/inactive social accounts can now be seen for users by admins (Previously only shown to current user).
• External auth ID field is now always available regardless of auth option set.