refactor GetFullText()

[certuna]

For some reason the mf.FullText and a.FullText fields are populated inside the sql Put() functions in the artist/mediafile repository code instead of where all other mf.* and a.* fields are populated.
Also, the getFullText() function used in Put() is not used for a.FullText in model/media_file.go

This refactoring:

• moves getFullText() ands its test into utils/sanitize_strings.go
• populates mf.FullText in scanner/mapping.go along with the rest of the mf.* fields
• populates a.FullText in album.go along with the rest along with the rest of the a.* fields
• uses the GetFullText() function also for a.FullText in model/media_file.go

[github-actions]

Download the artifacts for this pull request:

• binaries.zip
• js-bundle.zip

[deluan]

Also, the getFullText() function used in Put() is not used for a.FullText in model/media_file.go

There was a reason for that, I just don't remember what... I'll have to take a careful look at this before merging.