wasm: Import wasm-js-sb tests into WPT.
Adds a translation of our existing wasm-js-sb tests into WPT, along with some new tests too.
- Had to fix a bug in the wasm-module-builder.js
- Had to make js-sb a 'live' pref for WPT
- Had to expand the jstests harness to recognize JS prefs and apply them
Differential Revision: https://phabricator.services.mozilla.com/D219767
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1912523
gecko-commit: 93e2bed441a7b472040430ea36626aa4f45b0d7b
gecko-reviewers: bvisness