Parse the Gesture runefile

[Michael-F-Bryan]

This updates the parser so we can handle the new gestures Runefile. I also shuffled around the runefile.pest file to parse things with more fidelity, which will give analysis and codegen easier access to information it needs.

• Differentiate between integer, float, and string literals so that when you pass a parameter to a proc block we know what type it is (helps a lot with codegen because you don't resort to hacky string manipulation/parsing)
• Parse types (e.g. the F32[150, 2] in CAPABILITY<F32[150, 2], _>) in a more strongly-typed way so the analysis stage can reason about them better (e.g. instead of blindly comparing strings it knows something is a 150x2 f32 array)
• Made paths (e.g. for a proc block) have more structure than an opaque string so codegen knows how to add it as a dependency in Cargo.toml
• Removed the explicit whitespace parsing

Drive-by changes to the Runefile format:

• A CAPABILITY only really has an output type, so instead of writing CAPABILITY<_, F32>, we drop the _ to write CAPABILITY<F32>
• Rearranged instructions so it goes CAPABILITY<output_type> friendly_name RAND or MODEL<input, output> gesture ./gesture.tflite --some-arg 42

(I can easily revert these. It's just a case of rearranging a couple words and following the test failures)