Wasm components dependencies are case sensitive which can cause confusion

With a wac file that contains a reference to a dependency named `foo:bar-baz`, wac will look in the `deps` folder under a `foo` directory for a `bar-baz.wasm` file. However, if there is a difference in casing or a mix up in `-` vs `_` (e.g., `bar_baz.wasm` - the casing many toolchains will prefer to use for output binaries), the file will not be found.

At the very least, I think we could emit a warning when a file exists and only differs from the expected name in small ways. However, we may want to look for files with `_` instead of `-` as there shouldn't be any ambiguity between the two.

Start by tracing how a wac dependency such as foo:bar-baz is mapped into the deps/foo directory and expected bar-baz.wasm filename. Compare that lookup with files differing by case or using underscores, then define and test the intended warning or alternate-name behavior; the issue does not name a source file or test.

Written by the indexing model from the issue text.