Chore: Add user service method SetUsingOrg and GetSignedInUserWithCacheCtx (#53343)

* Chore: Add user service method SetUsingOrg

* Chore: Add user service method GetSignedInUserWithCacheCtx

* Use method GetSignedInUserWithCacheCtx from user service

* Fix lint after rebase

* Fix lint

* Fix lint error

* roll back some changes

* Roll back changes in api and middleware

* Add xorm tags to SignedInUser ID fields

pkg/services/contexthandler/auth_proxy_test.go

@@ -52,7 +52,7 @@ func TestInitContextWithAuthProxy_CachedInvalidUserID(t *testing.T) {
 	authEnabled := svc.initContextWithAuthProxy(ctx, orgID)
 	require.True(t, authEnabled)
 
-	require.Equal(t, userID, ctx.SignedInUser.UserId)
+	require.Equal(t, userID, ctx.SignedInUser.UserID)
 	require.True(t, ctx.IsSignedIn)
 
 	i, err := svc.RemoteCache.Get(context.Background(), key)
@@ -100,8 +100,8 @@ func (f *FakeGetSignUserStore) GetSignedInUser(ctx context.Context, query *model
 	}
 
 	query.Result = &user.SignedInUser{
-		UserId: userID,
-		OrgId:  orgID,
+		UserID: userID,
+		OrgID:  orgID,
 	}
 	return nil
 }