Currently the tool verifies:
* validity of plain_offset
* whether plain_size is smaller than encrypted_size
Change-Id: I9ec4fb5ead3356a196392c26ca377fcdb367138e
metabase has become a central concept and it's more suitable for it to
be directly nested under satellite rather than being part of metainfo.
metainfo is going to be the "endpoint" logic for handling requests.
Change-Id: I53770d6761ac1e9a1283b5aa68f471b21e784198