fix(core): build: support -t parameter correctly

Now allows any of the following. Quote marks are significant for
multiple tests with `-t`:

```bash
core/build.sh test:wasm --no-deps -- state-api debug-api
core/build.sh test:wasm --no-deps -- "state-api debug-api"
core/build.sh test:wasm --no-deps -t "state-api debug-api"
core/build.sh test:wasm --no-deps --test "state-api debug-api"
```

The `-t` / `--test` option takes a single string parameter which is
passed on to `meson test`, whereas the `--` "end of parameters" marker
allows arbitrary remaining parameters to be passed on to `meson test`.