TinyMCE's template plugin breaks after pat-tinymce loading inside pat-modal was fixed

[fredvd]

This is a regression caused by the fixes in #920 and #945 . These fixes solved that when TinyMCE loads in a modal (pat-modal), the menu's would no longer be visible or displaced because of ui_container not being passed.

Almost solved: With with ui_container being properly passed, the floating tinymce toolbar's styles menu for Mosaic's RichText tile does no longer work, which can be solved by passing in a different ui_container to snap to the mosaic tile: https://github.com/plone/plone.app.mosaic/issues/465

What now also breaks is the optional template plugin for tinymce as documented in the offical Plone docs at https://docs.plone.org/adapt-and-extend/config/templating.html#configure-templates.