Improvements to RequisiteParser (Packrat Parsing)

[Yogeb-tech]

These are the main improvements I've made:

• All parser rules are now defined in a single central registry, rather than being scattered across the codebase.
• Introduced a packrat parser structure that others can build on for more complex expression handling.
• Decoupled regex patterns from matcher logic, making rules easier to read and modify.

That said, I haven’t utilized the packrat parser as well as I should have. Ideally, each smaller parser could still keep its own regex patterns for now (change them later), but the next step would be adding a top-level packrat parser would handle AND/OR requirements, parentheses, and address any edge cases.

Currently:

• ParseRequirement() still uses manual strings.Split and recursion for AND/OR, and groupParens() to track parentheses
  • Therefore, adding a top-level packrat parser with NewAndParser, NewKleeneParser would be a good solution.
  • This top level parser would be able to parse through all the child parsers, replacing this recursive string parsing and greatly simplifying ParseRequirement
• groupParens() should be removed once packrat handles recursion properly
• Replacing parseGroup() usage in choice matcher with the packrat parser could also be beneficial

I would like to step away for this issue for a bit, if someone else could handle some of these changes, that would be great :)
I'm open to any suggestions or concerns about my proposed future changes.