Improve visual cues for TLS verification during cluster bootstrap

[simondeziel]

I really like the use of colors in the MicroCloud init/join sessions:

However, I think it could still be improved to leverage the brain's natural ability to do color matching. In those 3 terminals, I'd like it if the initiator's fingerprint (949f00313e81) could use a different color (blue?).

Also, once the initiator node displays the possible joining candidates, their respective fingerprint should have a color matching the one used when displaying it in the microcloud join sessions. I'd propose the joiners' fingerprints to be shown in yellow to avoid any confusion with "selected joiners" that turn the table's line to green:

[roosterfish]

We should not use yellow and red for other use cases than warnings and errors. This way those colors (and the respective text) really stands out in case something happens.
To make this more strict I have added #834. Before all of the bold text was also yellow which was confusing in my opinion as you weren't able to easily spot warnings.

Now all the warnings (and errors) also consistently use either the "x" or "!" as prefix for highlighting purposes.

If I am not mistaken Max was trying lots of colors in the past but blue didn't really fly on both dark and light terminal backgrounds.
We could potentially get rid of the green color highlighting when selecting table rows (only keep the green check mark?) but just highlight it using bold text.
This way we consistently use green only for "good"/positive information like fingerprints or the passphrases.

What do you think?

[simondeziel]

I'm fine with using only the green check mark for selected table rows, that sounds good.

I'm fine with any good color for the initiator's fingerprint, as long as we can easily distinguish it from joiners' fingerprints.