Make it possible to change entry types for existing nested entries from the Matrix inline-editable mode UI

[mmikkel]

Something I always wanted in Craft is the ability to change the block type (i.e. entry type) for existing blocks (i.e. nested entries).

With the Matrix entrification in Craft 5, this is finally possible! However, the entry type select is only available in slideouts and dedicated edit pages, which means that changing the entry type for nested entries edited in Matrix fields using the inline-editable view mode feels a bit more roundabout than it could be.

It'd be amazing if the entry type select could somehow be exposed in the inline-editable UI as well; ideally embedded inside the block action disclosure menu if possible.