SQLStore: Optionally retry queries if sqlite returns database is locked (#56096)

* SQLStore: Retry queries if sqlite returns database is locked

* Configurable retries

* Apply suggestions from code review

Co-authored-by: Christopher Moyer <35463610+chri2547@users.noreply.github.com>

pkg/services/sqlstore/sqlstore.go

@@ -455,6 +455,9 @@ func (ss *SQLStore) readConfig() error {
 	ss.dbCfg.CacheMode = sec.Key("cache_mode").MustString("private")
 	ss.dbCfg.SkipMigrations = sec.Key("skip_migrations").MustBool()
 	ss.dbCfg.MigrationLockAttemptTimeout = sec.Key("locking_attempt_timeout_sec").MustInt()
+
+	ss.dbCfg.QueryRetries = sec.Key("query_retries").MustInt()
+	ss.dbCfg.TransactionRetries = sec.Key("transaction_retries").MustInt(5)
 	return nil
 }
 
@@ -671,4 +674,8 @@ type DatabaseConfig struct {
 	UrlQueryParams              map[string][]string
 	SkipMigrations              bool
 	MigrationLockAttemptTimeout int
+	// SQLite only
+	QueryRetries int
+	// SQLite only
+	TransactionRetries int
 }