Add pcre2 ripgrep option

[dwelle]

Description of the Change

Added option to enable pcre2 ripgrep regex engine, as discussed in here.

NOTE: I haven't written any specs because I'm not sure what steps to take. Should I wrap all the specs in additional loop, same as prev PR has done with ripgrep support?

NOTE: cannot build Atom ATM so haven't tested the changes locally.

Benefits

Allows additional regex features such as lookbehind.

Possible Drawbacks

Enabling PCRE2 potentially incurs performance penalty, as explained on ripgrep's wiki, thus this PR does not enable it by default, and instead adds an option.

Applicable Issues

Addresses #571

Accompanying PR in atom core

[rafeca]

Thanks! I've done some basic testing and this PR seems to be working fine. Once the PR on atom/atom gets merged we can ship this one.

[dwelle]

Just reminding that this can now be merged, too.

[rafeca]

Thanks for the reminder 😃

[dwelle]

Mhm, seems it didn't work. I have both ripgrep and PCRE2 option enabled, but the parser complains the regex is invalid. Is that coming from ripgrep or atom? How come specs passed?

EDIT: hold on a minute. I've updated find-and-replace, but haven't updated core (still on stable). That must be it. So actually we should have waited with merging this PR, after all :)

[Arcanemagus]

The update of find-and-replace hasn't hit the beta channel yet, you can test it out on the nightly releases now, or wait for it to hit beta/stable during the normal release cycle.