This adds a lexer for the WIT IDL introduced by the WebAssembly Component Model specification

In addition to the tests added here, I tested it against the pretty expansive test suite of the wit-bindgen tool, and everything seems to be working as expected.

This adds a lexer for the [WIT](https://github.com/WebAssembly/component-model/blob/main/design/mvp/WIT.md) IDL introduced by the [WebAssembly Component Model specification](https://github.com/WebAssembly/component-model/)

In addition to the tests added here, I tested it against the pretty expansive [test suite](https://github.com/bytecodealliance/wit-bindgen/tree/main/tests/codegen) of the [wit-bindgen](https://github.com/bytecodealliance/wit-bindgen) tool, and everything seems to be working as expected.

Remove some trailing whitespace

7252ae5

Update test expectation after whitespace stripping

e88eace

Fix linting issue in wit lexer

c561c15

Appease more checks

d75ef57

Author

I think I now ran all checks locally, so I hope this will pass now. Apologies for the failures.