Dashboard Migrations: V20 variable syntax migration for data links and field options (#109203)

Co-authored-by: Ivan Ortega <ivanortegaalba@gmail.com>
Co-authored-by: Haris Rozajac <haris.rozajac12@gmail.com>

apps/dashboard/pkg/migration/schemaversion/migrations.go

@@ -5,7 +5,7 @@ import (
 )
 
 const (
-	MIN_VERSION    = 20
+	MIN_VERSION    = 19
 	LATEST_VERSION = 41
 )
 
@@ -38,6 +38,7 @@ type PanelPluginInfoProvider interface {
 
 func GetMigrations(dsInfoProvider DataSourceInfoProvider, panelProvider PanelPluginInfoProvider) map[int]SchemaVersionMigrationFunc {
 	return map[int]SchemaVersionMigrationFunc{
+		20: V20,
 		21: V21,
 		22: V22,
 		23: V23,