Add hprof file generator for WebAssembly heap

[konsoletyper]

Note that this generator would require additional external file that describes heap layout. Rationale: having this encoded in wasm file will increase its side and add security risks. Thus, only some intermediate heap dump can be generated by JS runtime. All user data, like contents of non-object arrays and non-object fields, should be removed, for security. Then, additional tool should be used, that takes this intermediate dump and heap layout descriptor and produces hprof file. This is how things work for C backend.