fix: Add explicit file extension to fix module resolution with Webpack

[susnux]

In some circumstances Webpack fails to resolve the module, this breaks e.g. forms 3.x.

So we need the explicit file extension to fix it.

[raimund-schluessler]

@susnux vitest has the same problem, see nextcloud/tasks#2450

[ShGKme]

It breaks Webpack build for Talk.

It cannot now require ('./locale/' + name); from the moment/min/moment-with-locales.js cause locales is not in the same directory and cannot be resolved from moment-with-locales.js.

WARNING in ./spreed/node_modules/moment/min/moment-with-locales.js 2159:16-50
Module not found: Error: Can't resolve './locale' in '<...>\talk-desktop\spreed\node_modules\moment\min'

[ShGKme]

But I cannot understand how it was supposed to work in moment...

How it was possible what

require('./locale/' + name)

Worked from here

moment/
├── locale/
├── min/
│  ├── locales.js
│  ├── locales.min.js
│  ├── locales.min.js.map
│  ├── moment-with-locales.js           <-- from here
│  ├── moment-with-locales.min.js
│  ├── moment-with-locales.min.js.map
│  ├── moment.min.js                     
│  └── moment.min.js.ma

Without any configs in package.json or patching require...

[ShGKme]

Fix: nextcloud-libraries/webpack-vue-config#533