Add support for 'Imprint' field

[dirigitive]

Support for Imprints was added to Metron as of August
https://metron-project.github.io/blog/imprint-support

[mizaki]

The problem is mokkari the library used to access Metron dropped support for Python 3.9 Metron-Project/mokkari@b5f51b3 which is not EoL and is still supported by ComicTagger.

So there are only a few options:
How "doesn't support python 3.9" is mokkari really? (I imagine it's a dep thing but don't know)
Wait for 3.9 EoL. (31 Oct 2025)
Not use mokkari. (A rewrite of a large portion of the talker would be required)
ComicTagger drops 3.9 support before EoL.