Iteration 4 for file detail & new sharing

[AndyScherzinger]

Iteration 1 can be found here: #2533 ☑️
Iteration 2 can be found here: #2573 ☑️
Iteration 3 can be found here: #2671

WiP for #2485 and collab with @tobiasKaminsky for adding commenting.

This PR/branch stack on top of fileDetails-3 until that one has been merged.

TODOs:

• add comment box UI
• send new comments to server (right away)
• update activities list after comment has been send to server (async)
• update activities list after comment could not be saved on server (error handling)

My idea behind the described to dos is to update the UI right away while reverting that in case the server couldn't store the comment. For starters I guess it'd be fine if it works synchronously to have it working and then improve upon that.

@tobiasKaminsky would you fancy taking on the part of client/server communication? ❤️

[tobiasKaminsky]

I already have a branch for comments, which is in top of file versions.
To not have too much confusion, can you simply remove the comment part from here?

[AndyScherzinger]

I already have a branch for comments, which is in top of file versions.
neither of these branches seems "visible" to me

To not have too much confusion, can you simply remove the comment part from here?
That is the only part of this PR, so you can just kill mine

On a general note
Why aren't the branches on GH plus opened PRs tagged as "1. developing"?

[tobiasKaminsky]

They will come one by one, but I have to polish them a bit, before putting them public ;-)

[AndyScherzinger]

terminated by any to come PR by @tobiasKaminsky