[DEV] Create preprocessor

[ArgosOfIthica]

Is your feature request related to a problem? Please describe.
Scripts frequently need to address many things in the same way; the 9 classes in TF2 for example. In normal paradigms, these are addressed with functions and lists, but these features are not compatible with the sparse computational power available to us. It is computationally optimal to simply deal with the 9 classes with 9 different services. Asking users to manually write this out is a huge inconvenience though.

Describe the solution you'd like
A painfully simple macro system. A preprocessor directive for ingesting a list of strings, and preprocessor directive for duplicating a string template where the template is instantiated with a list. We're aiming for 80/20 here; if you can't accomplish what you need with an unconditional template, use a scripting language.

Describe alternatives you've considered
Python3 cannot be sandboxed well enough to be considered for this purpose. Embedding other scripting languages would add a massive amount of complexity for nominal benefit.

[ArgosOfIthica]

Better late than never.

https://github.com/ArgosOfIthica/scalu/tree/feature/macros

Initial design is you can declare eagerly evaluated variables which you can use to put into other variables, or lazily evaluated templates defined with a simple inline syntax. There are compiler provided templates and variables that expose special functions and environment information; this would allow for fairly seamless additions or modules in the future. Exact syntax and features will be concretely defined as we progress.