fix(revset): Ignore ending newline in message(...)

[claytonrcarter]

As discussed in discord, this trims ending newlines from commit messages when they are compared with message(). In particular, this provides for more intuitive (to me) usage of message(exact:...) and message(regex:...) because I feel that most folks would assume that the commit message would not include the trailing newline anyway. This is a 1 line change and includes supporting tests.

Behavior without this change (on master):

❯ git commit -am 'My commit'
❯ git query 'message(exact:My commit)'
# nothing found
❯ git query 'message(regex:My commit$)'
# nothing found
❯ git query 'message(exact:My commit\n)'
abc123 My commit
❯ git query 'message(regex:My commit\n$)'
abc123 My commit

With this change:

❯ git commit -am 'My commit'
❯ git query 'message(exact:My commit)'
abc123 My commit
❯ git query 'message(regex:My commit$)'
abc123 My commit

Notes

• This only trims the subject (commit message), not the pattern. With this change exact:My commit\n will not work b/c the pattern will include the newline but the commit message won't. Trying to alter the pattern seemed like a can of worms, and I think that stripping just the message will make most usages more intuitive.
• I'm only stripping newlines from the end of the string. I considered trimming all whitespace but that felt unnecessary since git does that to commit messages already, and this just targets something that git adds on it's own.
• I have not done anything to consider line endings on Windows. Can you remind me if there's anything special I should be doing for those?

Thank you!

[arxanas]

Nice, thanks!