Upgrade tinymce (#18107)

* Upgrade tinymce

* Omit 'skin_url' instead of setting it to false

The option expect a string value. Instead of setting it to 'false' we
can just completly omit it.
Otherwise we get the following warning:
> Invalid value passed for the skin_url option. The value must be a string.

Although not explicitly mentioned in the migration doc, the stricter check / warning has
probably been introduced with v6.

* Disable pasting of images

From
https://www.tiny.cloud/docs/tinymce/6/migration-from-5x/#plugins-paste:

> A paste default has changed. The paste_data_images option now defaults to true.
> When paste was a plugin, this option was, by default, set to false, which prevented images being pasted from the local machine

* Update toolbar option names

---------

Co-authored-by: Pascal Jufer <pascal-jufer@bluewin.ch>

app/package.json

@@ -64,7 +64,7 @@
 		"@storybook/client-logger": "7.0.0-rc.4",
 		"@storybook/vue3": "7.0.0-rc.4",
 		"@storybook/vue3-vite": "7.0.0-rc.4",
-		"@tinymce/tinymce-vue": "4.0.7",
+		"@tinymce/tinymce-vue": "5.1.0",
 		"@turf/meta": "6.5.0",
 		"@types/base-64": "1.0.0",
 		"@types/codemirror": "5.60.7",
@@ -124,7 +124,7 @@
 		"react-dom": "18",
 		"sass": "1.59.3",
 		"storybook": "7.0.0-rc.4",
-		"tinymce": "5.10.7",
+		"tinymce": "6.4.1",
 		"typescript": "4.9.5",
 		"vite": "4.1.4",
 		"vitest": "0.29.3",