Provisioning: Allows specifying uid for datasource and use that in derived fields (#23585)

* Add uid to datasource

* Fix uid passing when provisioning

* Better error handling and Uid column type change

* Fix test and strict null error counts

* Add backend tests

* Add tests

* Fix strict null checks

* Update test

* Improve tests

* Update pkg/services/sqlstore/datasource.go

Co-Authored-By: Arve Knudsen <arve.knudsen@gmail.com>

* Variable rename

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

pkg/services/sqlstore/migrator/sqlite_dialect.go

@@ -2,7 +2,6 @@ package migrator
 
 import (
 	"fmt"
-
 	"github.com/mattn/go-sqlite3"
 	"xorm.io/xorm"
 )
@@ -95,6 +94,13 @@ func (db *Sqlite3) isThisError(err error, errcode int) bool {
 	return false
 }
 
+func (db *Sqlite3) ErrorMessage(err error) string {
+	if driverErr, ok := err.(sqlite3.Error); ok {
+		return driverErr.Error()
+	}
+	return ""
+}
+
 func (db *Sqlite3) IsUniqueConstraintViolation(err error) bool {
 	return db.isThisError(err, int(sqlite3.ErrConstraintUnique))
 }