feat: function calls

[baszalmstra]

This PR adds the ability to use function calls in Mun.

• Type inferencing for function calls
• Diagnostics on invalid parameter count and types
• Code generation to be able to call the functions
• IR generation tests
• Dispatch table generation
• IR call through dispatch table
• Integrate runtime and compiler in a test suite
• Optimize the shared object

[baszalmstra]

Function calls

[Wodann]

Some general feedback:

• You use a lot of comments to describe what a section of code or line of code is doing. I am a big proponent of writing self-explanatory code. By moving that code to separate functions whose names describe what happens, you can write a much more concise function body using those function calls.
• Merge commits can break tools such as git blame, so instead try to use git rebase
• Try to squash fix commits into their respective feature commits to clean up your history in a feature branch
• Try to create separate PRs where possible and order them such that they can be applied consecutively. E.g. first merge a PR for temporary directories. Then merge the PR for function calls that uses the previous PR. It ends up being easier to review smaller PRs with related materials.

[tdejager]

Very good, well done. There are a lot of files though so it was hard to do a thorough review, might be better to split some more stuff later on. But as always I'm impressed.