Remove redundant internal event in the User Permissions module (#573)

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#### Problem:
`NavUserAccountHelper.IsPermissionSetAssigned` doesn't work with
buffered inserts, so when user records are inserted without a `Commit`
(e. g. in tests), it throws the "User does not exist" exception. So far
this problem has been solved with an internal event that skips the call
alltogether in tests.

#### Solution:
Call `User.Get` before calling
`NavUserAccountHelper.IsPermissionSetAssigned` to make sure buffered
inserts are flushed.

#### Work Item(s) <!-- Add the issue number here after the #. The issue
needs to be open and approved. Submitting PRs with no linked issues or
unapproved issues is highly discouraged. -->
Fixes
[AB#497548](https://dynamicssmb2.visualstudio.com/1fcb79e7-ab07-432a-a3c6-6cf5a88ba4a5/_workitems/edit/497548)

src/System Application/App/User Permissions/src/UserPermissionsImpl.Codeunit.al

@@ -236,14 +236,15 @@ codeunit 153 "User Permissions Impl."
 
     procedure HasUserPermissionSetAssigned(UserSecurityId: Guid; Company: Text; RoleId: Code[20]; ItemScope: Option; AppId: Guid): Boolean
     var
+        User: Record User;
         NavUserAccountHelper: DotNet NavUserAccountHelper;
-        Skip: Boolean;
     begin
         if HasUserPermissionSetDirectlyAssigned(UserSecurityId, Company, RoleId, ItemScope, AppId) then
             exit(true);
 
-        OnHasUserPermissionSetAssigned(Skip);
-        if Skip then
+        // NavUserAccountHelper doesn't work with bulk (buffered) inserts.
+        // Calling a Get flushes the buffer.
+        if not User.Get(UserSecurityId) then
             exit(false);
 
         if NavUserAccountHelper.IsPermissionSetAssigned(UserSecurityId, '', RoleId, AppId, ItemScope) then
@@ -301,13 +302,4 @@ codeunit 153 "User Permissions Impl."
     local procedure OnCanManageUsersOnTenant(UserSID: Guid; var Result: Boolean)
     begin
     end;
-
-    /// <summary>
-    /// Allows the subscriber library to skip calls to NavUserAccountHelper in tests.
-    /// </summary>
-    /// <param name="Skip">Skip calls to NavUserAccountHelper.IsPermissionSetAssigned.</param>
-    [InternalEvent(false)]
-    local procedure OnHasUserPermissionSetAssigned(var Skip: Boolean)
-    begin
-    end;
 }

src/System Application/Test Library/User Permissions/src/TestUserPermissionsSubs.Codeunit.al

@@ -36,15 +36,5 @@ codeunit 130019 "Test User Permissions Subs."
         if CanManageUserSecIDs.Contains(UserSID) then
             Result := true;
     end;
-
-    /// <summary>
-    /// Skip calls to NavUserAccountHelper.IsPermissionSetAssigned, as it may fail in tests.
-    /// </summary>
-    /// <param name="Skip">Skip calls NavUserAccountHelper.IsPermissionSetAssigned.</param>
-    [EventSubscriber(ObjectType::Codeunit, Codeunit::"User Permissions Impl.", 'OnHasUserPermissionSetAssigned', '', false, false)]
-    local procedure OnHasUserPermissionSetAssigned(var Skip: Boolean)
-    begin
-        Skip := true;
-    end;
 }