* Add recording metadata provider
* Add recording MBID
* Save recording MBID during probing
* Set recording ID in probe result normalizer
* Add recording external media type
* Reimplement after changes in upstream
* Rename variable
* Rename variable
* Revert "Set recording ID in probe result normalizer"
This reverts commit 9dd18c8aba3f970a5816a13a33acf3d58b0e440f.
* Fix setting provider ID
* Simplify code
* Fix comment
* Add missing using
This is an universal solution for plugins to override how series are merged.
The reason to override is so we can set the same provider id on multiple items without merging them, while using another id for merging them. Having an (optional) provider id not tied to any online database allows plugins to use their own rules for merging series.