[js/test] align web test runner flags with ort.env (#19790)
### Description
the `npm test` flags are difficult to memorize, because they are
different to the `ort.env` flags. This change makes those flags align
with ort JS API. eg. `--wasm-enable-proxy` became `--wasm.proxy`.
Old flags are marked as deprecated except `-x` (as a shortcut of
`--wasm.numThreads`)
