JavaScript: Correctly await the TinyMCE initialization and avoid Tiny…

[thet]

…MCE double initialization.

[petschki]

Lgtm. Testsetup seems broken though.

[thet]

@fredvd tnx for your fix! since more is needed i created a separate PR and removed your commit from this one to keep it pure: #538

[frapell]

@thet Not sure if I am doing something wrong? I am pulling this branch, and after running yarn install and yarn build:webpack I am still seeing both tinymce being loaded (mosaic's one is a bit smaller though). Am I missing a step or something? (FYI I am simply opening a mosaic in edit mode with 1 richtext tile in it)

[mauritsvanrees]

I have rebased on master. That should fix CI.

[thet]

@frapell do is this a bare Plone 6.0 with only mosaic installed? Or are any other addons or tinymce plugins involved?

But this PR is about fixing the flaky initialization. Actually loading the TinyMCE editor twice is probably not fixed by this - this is more about the initialization which also happened twice.

[frapell]

@thet yup, fresh buildout.coredev from 6.0 with only mosaic.

Not sure what I need to test though, everything appears to be working ok, except I still see tinymce chunks being loaded twice as reported. But if this fix is unrelated to that, then everything looks fine.

[mauritsvanrees]

Thanks!