Related to issue #1047
After this it should be possible to build a working `packager` application from the `cmake` branch. Some further logging improvements may be needed to get full parity with the `main` branch in terms of ability to do verbose debug logging, but other than that everything is expected to work.
- Allow including Widevine and Common SystemID PSSH boxes
for PlayReadyKeySource.
- --playready_key_id and --playready_key flags are deprecated.
- --enable_raw_key_encryption already supports playready PSSH generation.
Addresses issue #245
Change-Id: I072d4f43a3239875959e4c5b1eb6854415d7367e