V8: TinyMCE - Images upload, drag & drop, and resize

[iOvergaard]

Description

This updates v8 with the latest bug fixes from v10 that we were able to cherry-pick regarding the TinyMCE editor and related media handlers.

What was fixed

• Drag & Drop images will now correctly call the imageProcessHandler and get a temporary file location for the image to append to a data attribute. If this process fails, TinyMCE will revert to storing the image as base64 which can get rather large, so this fix is very important.
• Resizing images will now call a new endpoint to get an updated crop URL to use in the editor ensuring, that we not only set width & height on the img element but also reflect that in the URL.
• Sometimes the rich text editor could not be activated on a grid editor if the id started with a number, which is not supported in HTML out-of-the-box, but by wrapping the selector in clams it works again.

[bergmania]

Can we do something in the client to check if there already is an embedded image and do the same as when it is dropped?

[iOvergaard]

V8 will now handle blobs as well after @Zeegaan managed to backport the fix from V10.

We will look into base64 -> blob migrations in their own pull requests. We will have to do individual fixes for client-side migrations for V7, V8, and V11+.

[Zeegaan]

LGTM 👍