Remove the top-level package class and general ergonomics

[Michael-F-Bryan]

It'd be more user-friendly if, instead of this...

https://github.com/wasmerio/wit-pack/blob/0b12fe02ca741cb34a74977aaf7b459220fb68fc/crates/wit-pack/tests/python-wasi/test_wabt.py#L6

https://github.com/wasmerio/wit-pack/blob/0b12fe02ca741cb34a74977aaf7b459220fb68fc/crates/wit-pack/tests/python-wasi/test_wabt.py#L18-L21

... people just needed to write this...

from wabt import bindings

wabt_library_instance = bindings.wabt()
wasm_result = wabt_library_instance.wat2wasm("(module)", WasmFeature.MUTABLE_GLOBALS)

CC: @syrusakbary

[syrusakbary]

After thinking more about this, I think your proposal is the right one:

from wabt import bindings

wabt_library_instance = bindings.wabt()
wasm_result = wabt_library_instance.wat2wasm("(module)", WasmFeature.MUTABLE_GLOBALS)

Why? We may need to get the memory filesystem inside of the wabt_library_instance in a way that is reusable:

wabt_library_instance.fs.read_conents("abc")
# OR at instantiation
wabt_library_instance = bindings.wabt(mount={".": LocalFilesystem(".")})