V14: Move towards get guid (#15889)

* Implement using keymap for member

* Remove current usages of GetUserById

* User userId resolver to resolve user key

* Refactor user repository to use GUID not int

* Add happy path test

* Remove user in cache when user gets updated

* Use await in async method

* Fix up according to review

* Update IMetricsConsentService.cs to have async method

* Fix according to review

* Fix more according to comments

* Revert "Fix up according to review"

This reverts commit a75acaaa

* Get current backoffice user from method

* Update user repository delete functionality

* Fix up more test

* Try to get user by id if key fails

* Add user key as required claim

* Fix tests

* Don't set claim in BackofficeController

* Create constant for the Sub claim

---------

Co-authored-by: kjac <kja@umbraco.dk>

tests/Umbraco.Tests.UnitTests/Umbraco.Core/Extensions/ClaimsPrincipalExtensionsTests.cs

@@ -18,6 +18,7 @@ public class ClaimsPrincipalExtensionsTests
         var backOfficeIdentity = new ClaimsIdentity();
         backOfficeIdentity.AddRequiredClaims(
             Constants.Security.SuperUserIdAsString,
+            Constants.Security.SuperUserKey,
             "test",
             "test",
             Enumerable.Empty<int>(),
@@ -55,6 +56,7 @@ public class ClaimsPrincipalExtensionsTests
         var backOfficeIdentity = new ClaimsIdentity();
         backOfficeIdentity.AddRequiredClaims(
             Constants.Security.SuperUserIdAsString,
+            Constants.Security.SuperUserKey,
             "test",
             "test",
             Enumerable.Empty<int>(),