Renames CustomPiwikJs plugin to CustomJsTracker

[sgiehl]

fixes #13604

[tsteur]

@sgiehl there used to be a plugin on the marketplace named CustomTrackerJs... just wondering if someone updates from Piwik 2.X to Matomo 4.X if this could cause any issues? I suppose that plugin would be simply overwritten? (which be kind of good since it would also automatically remove an outdated / not compatbile plugin) or is easier to rename it to CustomJsTracker?

[sgiehl]

Guess it would be overwritten, but not sure if some old files might remain 🤷‍♂
Not having a preference here. Can also rename it...

[tsteur]

Up to you. If we keep the name, might be worth testing what happens when upgrading from Piwik 2 and such a plugin existed. Might be easier to maybe rename it?

[sgiehl]

renamed it again. Need to update the UI tests again, I guess. But should be ready for another review

[tsteur]

Left a few minor comments, nothing major. Mostly around docs.

Adjusted already 6 or so internal plugins. Be good to make the changes in tag manager and resolve the open issues then be good to merge

[sgiehl]

@tsteur applied the feedback

[tsteur]

Looks good in general @sgiehl some tests will need fixing though

[sgiehl]

Guess tests are failing because the changes in tagmanager are needed. will push a submodule change to prove that.

[sgiehl]

Tests seem to pass again. Before merging we need to merge matomo-org/tag-manager#220 and update the submodule ref here.