Bring parity to RTE & PTE

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What does this MR do and why?

Currently the plaintext editor and Rich Text editor toolbars have some dissimilarity, this MR adds:

• A collapsible button addition to RTE, similar to the plain text editor.
• Adds a visual separator between the "Add a quick action" and "Insert comment template" buttons in plain text editor.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

Related to #507377