Expose capability metadata & tag

It would be nice if you could view the capability metadata and tags of pointers and registers somehow. I think for registers we might be able to create extra registers like `x1_meta`, `x1_tag` and so on. Not sure how do to it for pointers. That might require extensions to LLDB and CodeLLDB.

The issue does not identify files, tests, or entry points. Start by determining how register and pointer capabilities are represented and whether LLDB or CodeLLDB extensions are required; the work is done when both metadata and tags can be viewed for the supported capability types.

Written by the indexing model from the issue text.