Implemented annotations display in dexdump.

Rationale:
Showing this in true dexdump style as a separate construct
under switch -a (rather than interpreting the data and showing
each annotation where it is used). Also added new test to
cover many more value encodings in static fields.

BUG=28981655

Change-Id: I6d7d44cbd358d9880aab78812471bdb0dc6b6ad8