Make tags feature optionnal with a trait

[Tofandel]

Summary

Right now the tags relation is defined as morphToMany and the TaggableTrait is included on each twill model (even translations and slugs)

This doesn't make much sense from a separation of concern standpoint and likely causes unnecessary overhead

Describe the solution you'd like

A trait HasTags or IsTaggable instead of the method included in each model

Additional context

Right now this causes issues (as well as pollutes the generated phpdoc) when using Relation::enforceMorphMap and laravel-ide-helper because the tags method is on models which have no business in being included in the morphMap

Error resolving relation model of App\Models\Slugs\VideoSlug:tags() : No morph map defined for model [App\Models\Slugs\VideoSlug].
Error resolving relation model of App\Twill\Capsules\Pages\Models\PageSlug:tags() : No morph map defined for model [App\Twill\Capsules\Pages\Models\PageSlug].
Error resolving relation model of App\Twill\Capsules\Pages\Models\PageTranslation:tags() : No morph map defined for model [App\Twill\Capsules\Pages\Models\PageTranslation].

This would need to be on v4 because of the breaking change

Maybe we also need different levels of Twill\Model maybe one for Slug and one for Translation just like we already have one for Revisions to avoid the overhead of the base model in Translation and Slug models, this can be done in v3 without a breaking change and would already solve a big part of the issue at hand