* Add .wasm cc artifact executable extension

This allows creating a custom cc_toolchain that compiles to WebAssembly that outputs a wasm file with the standard extension, without needing to have a genrule that renames the file

Closes #16091.

PiperOrigin-RevId: 503921110
Change-Id: I3ed9e50a945d2e415e2ab34bd99ceea481c987f0

* Add .wasm cc dynamic library extension

Similar to #16091 except also allow the `.wasm` extension for dynamic libraries.

Closes #17374.

PiperOrigin-RevId: 507668339
Change-Id: Id85f98bb804e573e5f93a922b67baf75a22baf16

---------

Co-authored-by: Scott Bennett <scottbennett@google.com>
Co-authored-by: kshyanashree <109167932+kshyanashree@users.noreply.github.com>