[BUGFIX] CKEditor: show selectAll button in preset "full"

Resolves: #85383
Releases: master, 8.7
Change-Id: I108167eef9ba1028991d332d952c68cecd0fa649
Reviewed-on: https://review.typo3.org/57369
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Josef Glatz <josef.glatz@typo3.org>
Tested-by: Josef Glatz <josef.glatz@typo3.org>
Reviewed-by: Riccardo De Contardi <erredeco@gmail.com>
Tested-by: Riccardo De Contardi <erredeco@gmail.com>

typo3/sysext/rte_ckeditor/Configuration/RTE/Full.yaml

@@ -51,6 +51,7 @@ editor:
       - font
       - find
       - bidi
+      - selectall
 
     removePlugins:
       - image