Refactor expand dry_run types to return coef rate

Adds the functionality to return the rate cost due to
coefficients without doing full search of all modes.
This will be subsequently used in various experiments,
including in new_quant experiment to search quantization
profiles at the superblock level without repeating the
full mode/partition search.

Change-Id: I4aad3f3f0c8b8dfdea38f8f4f094a98283f47f08
5 files changed