Add support for >=, <= and == operators in selections

[pslacerda1]

Fix #477.

Edit: in love with claude.ai

[JarrettSJohnson]

Just FYI, I am happy with the spirit of the PR, but just note that we're about to transition over to the next version. And since this has such a large scope-of-effect since this touches fundamental selection logic, this will be deferred until after we release (or branch for) 3.2.

[JarrettSJohnson]

Seems like 95% of this PR is code changes that are just refactoring and not needed to support this feature? If so, can this be split into multiple commits or PRs?

[pslacerda1]

I rather prefer to increase the test coverage in this area than revisit code that is already done. May this be an option?

[pslacerda1]

@JarrettSJohnson may this code be accepted with additional test cases? Or should I really split this commit into refactoring and fixing #470?

[JarrettSJohnson]

I didn't know this blocked the other PR. But I think either way, most of this PR still touches too much selection code--even if you were to add additional tests, who knows what else could regress that we haven't considered. IMO, this will probably have to wait until the next cycle.

[pslacerda1]

Alright, let keeps this in standby mode...