feat: prepend relevant debug infos to logs

[nicodh]

The item "View log" in Settings->Advanced should open a dialog showing a (limited?) dump of the current log entries and relevant infos about the system, storage etc. in a textarea, similar to the view in the mobile clients.

The text should be editable and a share and a copy button should be available.

A warning should be shown: "This log may contain sensitive information. If you want to post it publicly you may examine and edit it beforehand"

For context see chatmail/core#7486

and

#5756

[r10s]

once this is done, we can make the "About Dialog" nicer, and turn it into smth that avg user without issues expects at that place. and smth that fits better overall.

i left the "claim" as is for now, there could be a logo, but this should be the base.

"View Log" would open the dialog discussed above then, where nerds and devs find all the info from #5756 - and where devs can send avg user to, sending info+log out for debugging