[ui] Add comment actions modal feature

[benfurber]

Component infos

Description

At the moment, the chunky comment actions of edit/delete are shown, which especially on mobile get in the way.

Add a modal to CommentDisplay in the component library for the completion of these actions.

It should be implemented on both mobile and desktop.

Page related

As we're changing DBs at the moment, there's two sets of commenting components, only update CommentDisplay which is used on questions as the old components won't be around for long.

Mockup

Here is also the Figma link, to see the measurements, colors and see the behaviour by playing the prototype.

Here in the design there are 4 options, accounting for possible future expansion of the actions. For now only the Edit and Delete should be there.

Feel free to reuse the edit and delete icons that already exist in the current implementation.