Cloud Migrations: Create new service for cloud migrations (#80949)

* introduce feature toggle

* create base service structure

* fix sample metric

* register metrics

* add to codeowners

* separate api dtos from service models

* remove leading newline

pkg/services/cloudmigrations/api/models.go

@@ -0,0 +1,10 @@
+package api
+
+type migrateDatasourcesRequestDTO struct {
+	MigrateToPDC       bool `json:"migrateToPDC"`
+	MigrateCredentials bool `json:"migrateCredentials"`
+}
+
+type migrateDatasourcesResponseDTO struct {
+	DatasourcesMigrated int `json:"datasourcesMigrated"`
+}