[$100 bounty] Remove setproctitle dependency

[adeebshihadeh]

Replace setproctitle with our own small helper in common/. Just needs to work on Linux.

[markypizz]

Curious if I'm trending in the right direction. Thanks!
#32666

[jyoung8607]

Truly replacing Linux setproctitle() requires clobbering the original argv[], which is some real sausage-making. However, @cl0cks4fe has taken a shot in #32691.

The other approaches are setting a thread title. htop doesn't show them because it's configured not to. IMO we should fix the htop config, because then we'll actually start seeing see the thread names we're already setting in camerad, loggerd, and boardd. Then we can migrate setproctitle() users to setting thread titles, and dispose of the dependency that way.

[markypizz]

Agreed with the above. htop is looking at /proc/{pid}/cmdline, which can't be changed other than clobbering argv and the mess associated with it. Is the setting of the title purely for cosmetics or for some other reason?