improvement: a11y: turn more elements into <button>s

[WofWca]

• improvement: turn clickable items into s
• improvement: turn clickable items into s
• improvement: a11y: turn quote into
• refactor: add comment about a11y
• improvement: turn autocrypt msg into
• improvement: turn delivery status into

[nicodh]

It is a bit weird now that the reactions and the context menu is now reachable with key navigation but only, if the cursor is on the right height to "activate" these buttons. I can activate the context menu with the "menu" button on my keyboard but I can't navigate on the menu. Is the plan to implement these missing features also?

Nevertheless this PR is an improvement and a good step. Other optimizations can follow later...

[WofWca]

the reactions and the context menu is now reachable with key navigation but only, if the cursor is on the right height to "activate" these buttons

There are ways to activate "react" and the context menu with just the keyboard, so I think there is no need for the extra ways to do that with the controls that appear on hover. But this can be achieved by adding :focus-within on top of :hover if needed.

but I can't navigate on the menu

Even with arrow keys?

[nicodh]

the reactions and the context menu is now reachable with key navigation but only, if the cursor is on the right height to "activate" these buttons

There are ways to activate "react" and the context menu with just the keyboard, so I think there is no need for the extra ways to do that with the controls that appear on hover. But this can be achieved by adding :focus-within on top of :hover if needed.

For me it is like this:
I can focus (via tab key) to the message with the reaction

but the next tab jumps to the attach button in the message input field

I can't focus the other messages, (only when I go with the cursor near a message which makes the reactions button visible)

but I can't navigate on the ,

Even with arrow keys?
My fault, I tried tab key. Works with arrow keys.

[WofWca]

Making each message keyboard-navigable is taken care of in #4294.