Refactor Wasmtime's profiling support

[alexcrichton]

This commit refactors the profiling support for existing agents in Wasmtime. The end goal was to handle #6328 and I ended up doing a fair bit of other cleanup along the way. The profilers are now all centered around "load a single function" rather than dealing with both modules and trampolines. The shared logic of parsing an ELF file is located in one place now in shared support across all profilers.

This also applies refactorings such as removing DWARF support for jitdump which while not problematic hasn't been necessary for me historically. Additionally Wasmtime's support for DWARF is too buggy to enable so it's not getting any use anyway.

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It looks like you are changing Wasmtime's configuration options. Make sure to
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[fitzgen]

Very nice!