Add API to convert wasm-opt command-line options to OptimizationOptions

[brson]

The easiest way for projects to integrate the wasm-opt API will be if they can continue using their existing CLI arguments instead of using the builder API directly. e.g. I imagine cargo-contract will want to continue having the ability to optionally use the wasm-opt CLI for some period until they are confident removing that code. To avoid having two code paths, it will be easier for them if the wasm-opt API can just handle the same CLI arguments they are already using.

• Create an integration module with a single function, run, that accepts std::process::Command
• Iterate over all the arguments of that command to create an OptimizationOptions, while also pulling out the input file, output file, input sourcemap, and output souremap paths.
• Call OptimizationOptions::run
• Return an error for any command line options that aren't understood.

We implement this on a best-effort basis to support whatever actual integrators need, for now just cargo-contract. It doesn't need full fidelity with exactly everything the wasm-opt CLI can parse, as long as integrators can craft a single command that works with both the "real" wasm-opt and the API.

cargo-contract needs these arguments:

• the input file
• "-o" output file
• "-On"
• "--zero-filled-memory"
• "-g"

We can get that working, and should probably go ahead and support all CLI equivalents for everything the builder API supports.

[brson]

I've started this.

[brson]

Done.