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.