wasm-compose: deduplicate identical modules

Now that we've implemented [shared-everything linking](https://github.com/WebAssembly/component-model/blob/main/design/mvp/examples/SharedEverythingDynamicLinking.md) as part of `wit-component` (see https://github.com/bytecodealliance/wasm-tools/pull/1133), it would be nice if `wasm-compose` could check for identical modules and deduplicate them.

For example, when composing two components created by `componentize-py`, both components will [1] likely have identical copies of `libpython311.so`, `libc.so`, `libcomponentize_py_runtime.so`, etc., each of which could be deduplicated.

[1]: If it turns out two components produced by the same version of `componentize-py` contain libraries that _aren't_ identical, I'd consider that a bug to be fixed.