It return an extension of RsMsgMetaData with `isDownloading` flag to check if is being downloading

Refactor the code adding there stuff

In order to do alway same actions:

1. subscribe
2. Request sync
3. Set storage and sync periods time (to implement)

Using an already existing method on the cache

Refactor `getIdDetails` to retry using `/home/bolet/Z_LINKS/proyectosGit/elrepo.io/elrepo-lib/lib/src/repo_lib/identities.dart`