Allow specifying wasm features to be enabled (or enable all features) in wac

[tanishiking]

Currently, wac uses a predefined set of Wasm features when creating a Validator.
Specifically, it enables the component_model feature alongside the defaults,

wac/crates/wac-types/src/package.rs

Lines 203 to 206 in d0eb3d4

	let mut validator = Validator::new_with_features(WasmFeatures {
	component_model: true,
	..Default::default()
	});

wac/crates/wac-graph/src/graph.rs

Lines 1228 to 1231 in d0eb3d4

	Validator::new_with_features(WasmFeatures {
	component_model: true,
	..Default::default()
	})

When this configuration doesn't contain, for example gc, wac fails to validate when it runs against the Wasm components that depend on gc.

(Context: I'm trying to support Wasm Component in Scala (using WasmGC), and struggled to use wac with it)

proposal

• (1) Allow to specify which wasm features to be enabled (using --features flag as wasm-tools does), or
• (2) Enable all features as I do in the workaround below

Workaround

A workaround involves modifying the Validator to use WasmFeatures::all():

- Validator::new_with_features(WasmFeatures {
-     component_model: true,
-     ..Default::default()
- })
+ Validator::new_with_features(WasmFeatures::all())

[calvinrp]

Seems reasonable. Would you like to create a PR?

[tanishiking]

@calvinrp Sure :) Do you think enabling all features is reasonable?

I opened a PR that implements (2), but if it should be (1), let me know