build: fix path voodoo in icu-generic.gyp

Intention was to get to `PRODUCT_DIR` so no need to do path voodoo
Also added `'msvs_quote_cmd': 0` and more precise quoting

PR-URL: https://github.com/nodejs/node/pull/11217


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>
Reviewed-By: Steven R Loomis <srloomis@us.ibm.com>