FEATURE REQUEST: Add an interface for embedding tags in MKV files

We'd love to have an interface (somewhere in the config tag) that allows users to embed metadata into specific MKV tags.

Eventually it'd be great to have acces to the entire [NMAAHC Standard Tag Set](https://github.com/NMAAHC/mkvnote/blob/main/README.md#nmaahc-standard-tag-set). However, for now just these tags would be incredibly helpful:

- ENCODER_SETTINGS
- ENCODED_BY
- _PRE_TRANSFER_NOTES
- _TRANSFER_NOTES

Additionally, the DATE_DIGITIZED tag should have a toggle that allows it to be automatically updated with the current date, and the DATE_TAGGED tag should automatically be updated with the current date if tagging occurs.

paging @BleakleyMcD to see if he has anything to add