Added nested conditional filter support

[jamessimone]

No description provided.

[jongpie]

@jamessimone I just reviewed this again, and I love it! I think I'm good with the class & enum names - I'll go ahead and merge this into my branch for PR #39, and then I'll release the new packages this week.

Thanks again for adding this!

[jamessimone]

Awesome, sounds good!

[jongpie]

@jamessimone I'm going to revert this PR for the moment - it looks like there wasn't an assert in the new test method, so I added System.assertEquals(expected, actual.getQuery()); (plus a small change to include the Name field in the expected query, since Query auto-adds the name field.... apparently), and the generated where clause is a bit jumbled.

• Expected: `SELECT Id, Name FROM Contact WHERE LastName = :bindVar0 OR LastName = :bindVar1 OR (FirstName = :bindVar2 AND (LastName != :bindVar3 OR LastName != :bindVar4))
• Actual: SELECT Id, Name FROM Contact WHERE (AND (FirstName = ':bindVar2' OR (LastName != ':bindVar3' LastName != ':bindVar4'))) AND (LastName = ':bindVar1') AND

In the 'actual' value, there are some extra AND strings being added, and more notably, the ordering of the filter string is different. I think this is all related to some existing logic in the SOQL class that does some sorting on the list of QueryFilter when generating the query string via Query.getQuery(). It's been so long since I worked on some of this code, I don't remember why exactly it's doing the sorting, but I know it was a purposeful decision that probably made sense when it was added 5 years ago😅 ), and I don't want to risk breaking existing behavior by changing it right now. I'm planning to do a big refactor of the entire codebase over the coming weeks; I'll re-merge your changes once I've dived a little deeper into the code & done some cleanup.

[jamessimone]

Sure, makes sense!