Annotated tag support (Java and REST APIs, UI)

Nowadays the REST API has just some features related to tags.
It would be great if it includes:

1. create tags remotely, both lightweight and annotated tags, using the REST API without having to clone the repo (the equivalent of the branch utils component but with tags).
2. include the annotated tag messages in api results.

Similarly, the UI shows tags, but has no visual indicators of whether they're annotated or lightweight, and doesn't offer messages.

Lastly, the Java API (Tag) also provides no access to tag messages or types (although lightweight and annotated tags can be distinguished because an annotated tag will have a getHash() value where a lightweight tag will not).