Improvements to the camera metadata structure

Improvements to the camera metadata structure

- Add vendor_tag_query_ops_t as argument to methods inside it.

- Add version and flags fields

- Add sorted flag; additions and appends are not sorted, and thus
  reset the flag.

- Add sort method, which sets the sorted flag.

- Add find-by-tag method, which uses a linear search on a non-sorted
  buffer, and a binary search on a sorted buffer.

- Change dump method to take in a fd, like the HAL-level dump methods
  do.

- Minor revisions to tag definitions, including a few enums for
  enumerated-value tags.

Change-Id: I5f37e326519bda032cb3362da4ab3bf50eb98b4e