[VOTE] Replace updated_fragment_offsets with roaring bitmap

[wjones127]

The transaction field updated_fragment_offsets is a list of int32 directly in a protobuf definition. This isn't particularly efficiently encoded, and can make transaction files very large.

This vote adds a new field: map<uint64, bytes> updated_fragment_offset_bitmaps = 10; to replace that one.

These fields are actually only used by the committer of the transaction, and not used by other writers when doing conflict resolution. Because of this, there isn't much risk to changing which field is used. Older writers will still be able to do conflict resolution just as they have before.

PR: #7432