Stats: Stop counting the same user multiple times (#26777)

* Stats: Cache based stats implementation

* Stats: Correct logic and add larger scale test

* Stats: linter

* Stats: SQL implementation

* Stats: cleanup SQL

* Stats: Tab -> Spaces

* Update pkg/services/sqlstore/stats.go

Co-authored-by: Sofia Papagiannaki <papagian@users.noreply.github.com>

* Stats: Quote 'user' table with dialect.Quote

* Stats: Ensure test is run as integration test

* Stats: Use boolean value

...because if (v) { true } else { false } is unnecessary at best.

Co-authored-by: Sofia Papagiannaki <papagian@users.noreply.github.com>

pkg/models/stats.go

@@ -92,13 +92,15 @@ type GetSystemUserCountStatsQuery struct {
 	Result *SystemUserCountStats
 }
 
-type ActiveUserStats struct {
-	ActiveUsers   int64
-	ActiveAdmins  int64
-	ActiveEditors int64
-	ActiveViewers int64
+type UserStats struct {
+	Users   int64
+	Admins  int64
+	Editors int64
+	Viewers int64
 }
 
-type GetActiveUserStatsQuery struct {
-	Result *ActiveUserStats
+type GetUserStatsQuery struct {
+	MustUpdate bool
+	Active     bool
+	Result     UserStats
 }