Run eslint with webpack for vue files

[raimund-schluessler]

This brings back running eslint on vue files when webpack runs (dev, watch, build) which got lost with #2594.

Before:
See that eslint only reports lint problems in js files when e.g. `npm run watch' runs.

After:
See that eslint now also reports lint problems in vue files when e.g. `npm run watch' runs.

[skjnldsv]

So, we actually are moving away from this :)
To have those as a separate step nextcloud-libraries/webpack-vue-config#318

[raimund-schluessler]

So, we actually are moving away from this :) To have those as a separate step nextcloud/webpack-vue-config#318

Hm, ok. I just found it very helpful with fixing many linting errors in #2637 to immediately only see the ones I didn't fix yet. But I guess that's an edge case. Closing then.