Add support for Link fields

Problem/Motivation

Support for Link fields would be similar to handling src (in <img>) and href (in <a>) and feels like something Link Magician should do :)

Proposed resolution

Add support.

User interface changes

Adds configuration settings for 'Link field' in the Media Lookup Order section and Not Published section.

Tracking changes

This introduces data that looks a bit different in the current before/after (link_magician_link table) and tag (link_magician_skip) fields in tracking.

Test

You need to have at least one AKA configured ("https://example.net" used below; don't forget to click the save button).
You'll need to have a content type that supports the Link field (if you're adding it in a testing environment, I'd recommend setting it to allow multiple)
You'll also need to have/create

1. A media entity with an alias; for example /testing/media
2. a page with an alias: for example /testing/page

Create/edit a page to include several variations of the page and media links (replace NNN/MMM the node/media ids for the above) in Link Fields

1. /testing/media
2. entity:media/MMM
3. https://example.net/testing/media
4. /testing/page
5. https://example.net/testing/page

Run link magician on the parent page: drush link_magician:tidy nodeid --nodeid=NNNN
See the "Updated" results (/admin/link_magician/tracking/results/updated/{batchid}). You should see updates to the links.