Linux build failing

[Frost-54]

Hi, I encountered a few issues when building Razix on Linux:

1. Some MSVC specific extensions are used(e.g omitting template on dependent types)
2. Some platform specific stuffs(e.g macros)
3. Some APIs are only implemented for Windows(e.g RZSplashScreen, entry point)
4. Headers are not self-contained(not fatal, but it makes working in VSCode + clangd harder)
5. Build system related issues(e.g hard coded paths)
6. Some extensions use deprecated Qt APIs that are removed in Qt6.
7. Tracy's embedded imgui conflicts with our imgui(can be fixed by adding tracy/ prefix when including tracy headers).

Any plan on fixing these? I am happy to work on these. Thanks!