Modularizing skript-parser

[Mwexim]

Roadmap to modularize skript-parser

1. Lexical modules

• [ ] Lexical structure manipulation
  • [ ] Allow addons to hook into this process and change it
  • [ ] Possible rework of FileElement and FileSection
  • [ ] Rework comment parsing
  • [ ] Refactor/restructure this process to be more optimized and user-friendly (StructureParser?)

2. Registration modules

• [ ] Annotation registrations?
  • [ ] Remove/rework SkriptRegistration class completely (as it is pure convenience either way)
• [ ] Enum registrations
• [ ] Overriding elements easily

3. Parsing and SyntaxElement modules

• [ ] Control flow improvements
  • [ ] Rework of Finishing, SelfRegistrable and Continuable
  • [ ] Rework of ArgumentSections and iterative sections
  • [ ] Exiting function (perhaps instead of SelfRegistrable?)
• [ ] Native Async support
  • [ ] AsyncEffect and AsyncSection, perhaps AsyncExpression
  • [ ] Rework all async events and effects to be safe, reliable and optimizable
• [ ] Operators
  • Defined by context and type parameters (nothing else)
  • [ ] Overriding system to override certain contexts with other type parameters
  • [ ] Somehow link ContextValue and Operator functionality (although this is probably not necessary)
• [ ] Pre- and post-parsing triggers (although this might take it too far)
  • [ ] Make a new parsing chain with priority queue (for example, when parsing an expression, first parse as a list, then as a variable, then as registered expression, then as context value)
  • [ ] Allow addons to hook into this system
• [ ] Rework tags
  • [ ] Rework tag registration, parsing and matching/initialization completely
  • [ ] More customizability, while adding some sort of pattern to it.
  • [ ] Make them completely independent of VariableString and require a specific call to apply them.