feat: OPTIC-181: refactoring of soft-delete from Users to OrganizationMembers (#4927)

* feat; OPTIC-181: refactoring of soft-delete from Users to OrganizationMembers

* Remove is_deleted and rely on deleted_at, add migration

* Linter formatting fixes

* Update all user.organization queries to filter out deleted user org memberships

* Update soft_delete to update user's active_organization

* Add organization member mixin for permissions purposes

* Move soft-delete api to label studio and move test case to org test file

* Move soft delete api endpoint to remove from list endpoint to its own detail view

* Linter fixes

* Add helptext to migration

* Updated object permissions check to account for all write methods (non-safe methods)

* Revert accidentally commited change

Co-authored-by: bmartel <brandonmartel@gmail.com>

* Update user context to pass in users instead of request (which sometimes breaks previous context)

* Update user org member queries for efficiency

* Add comment

* Fix issue where deleted user can log back in, add tests validate fix

* Add fix to reinstate user via email invite flow

* Add release of task locks for soft-delete users

* Fix query

* Remove deleted soft-delete users endpoint from all_urls

* check request in context before attempting to use it

* Add serializer context to areas using UserSerializer

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Co-authored-by: bmartel <brandonmartel@gmail.com>
Co-authored-by: bmartel <bmartel@users.noreply.github.com>