Add support for preproc style macro's as system constants

[WolfGangS]

WARNING

THIS PR SHOULD NOT BE MERGED UNTIL AFTER #41 and #42

It contains the work from those pr's as well to avoid merge conflicts

Main

This adds support to the slua preprocessing for the LSL preproc's predefined macros

This functionality is being a config switch and off by default.

When enabled an extra definition file that contains the constants is generated and loaded into luau-lsp

This pr also adds support to the lexer for luau's string interpolation, allowing macro's to be inserted into strings.

And includes test for the same. Along with an update to the preproc documentation to reflect SLua's constants support.

Example script

Source

ll.OwnerSay(__AGENTID__)

Output

ll.OwnerSay("677bf9a4-bba5-4cf9-a4ad-4802a0f7ef46")

String interpolation example

Source

ll.OwnerSay(`The scripters key is {__AGENTID__}!`)

Output

ll.OwnerSay(`The scripters key is {"677bf9a4-bba5-4cf9-a4ad-4802a0f7ef46"}!`)