Runtime Mod Support PR 1 (Mod framework and mod loading)

[Mr-Wiseguy]

This PR implements all the base functionality in the modding framework (besides LuaJIT recompilation of mod code). This includes:

• Setting up a mod game ID when registering a game
• Scanning for mods
• Opening .nrm mod files and loose mod folders
• Parsing the mod manifest
• Exposing a function to get the details for detected mods
• Enabling and disabling mods
• Loading mod data and performing any necessary R_MIPS_32 relocations
• Loading offline-compiled mod code
• Loading additional mod dynamic libraries
• Resolving mod dependencies, including connecting mod imports and exports as well as events and callbacks
• Patching base recomp functions with hooks to jump to mod code for x86_64
• Detecting conflicts between mods (when two mods patch the same base recomp function)

The following functionality will come in later PRs:

• Allowing a project to register additional accepted mod file extensions (so they can use this system for RT64 texture pack support), with an option to generate a default manifest if none is present
• Implementing jump hook patches on ARM64
• Detecting conflicts between mod patches and base recomp patches (by scanning the patch overlays to gather a list of patched functions)
• Recompilation of mod code into LuaJIT
• Integrating the LuaJIT library into the runtime for running recompiled LuaJIT mods