feature request: b4 option to sort trailers

[floatious]

It would be nice if there either was an option for b4 to sort trailers by default,
or to add an option to do so.

After using $ b4 shazam -s -t

I get:
Reviewed-by: aaa
Tested-by: aaa
Reviewed-by: bbb
Tested-by: ccc
Reviewed-by: ddd
Signed-off-by: eee

I don't know if this is because I used -t (some trailers were given on the cover letter).

But at least I would prefer to have:
Tested-by: aaa
Tested-by: ccc
Reviewed-by: aaa
Reviewed-by: bbb
Reviewed-by: ddd
Signed-off-by: eee

So that the R-b and T-b are grouped together.

[mricon]

This is supported (within the custody boundaries) by the trailer-order config option, see https://b4.docs.kernel.org/en/latest/config.html.