Annotation: Optionally allow storing longer annotation tags (#54754)

* Annotation: Optionally allow longer annotation tags

* Do not accept configuration lower than today's default (500)

* Apply suggestion from code review

pkg/services/annotations/annotationsimpl/annotations.go

@@ -17,10 +17,11 @@ type RepositoryImpl struct {
 func ProvideService(db db.DB, cfg *setting.Cfg, tagService tag.Service) *RepositoryImpl {
 	return &RepositoryImpl{
 		store: &xormRepositoryImpl{
-			cfg:        cfg,
-			db:         db,
-			log:        log.New("annotations"),
-			tagService: tagService,
+			cfg:               cfg,
+			db:                db,
+			log:               log.New("annotations"),
+			tagService:        tagService,
+			maximumTagsLength: cfg.AnnotationMaximumTagsLength,
 		},
 	}
 }