[browser] Support emitting WebAssembly symbols to build output by WasmSDK

[maraf]

The WasmEmitSymbolMap=true tells emscripten to generate symbols file, but WasmSDK isn't promoting to build output. The generated file remains in obj. Default version of the file is part of runtime pack as well.

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
See info in area-owners.md if you want to be subscribed.

[pavelsavara]

Also add asset.hash and fingerprint.