Feature(config): support translation without needing to specify availableLangs

[dkimmich-onventis]

Is there an existing issue for this?

• [X] I have searched the existing issues

Which Transloco package(s) will this feature affect?

Transloco

Is your feature request related to a problem? Please describe

In our company, we have a third party tool where the translations are maintained. The developers add the keys in the english language and upload the keys to the tool. Someone else will take care that the keys will be translated in all supported languages. During build, we download all the translation files. However, the developers don't care which languages are supported, either the translation file is there, or it's missing and we run the fallback logic. Transloco though forces us developers to maintain a list of all supported languages, which is annoying for us as it's not our responsibility. Adding new languages now requires code changes, which complicates this process unnecessarily.

Describe the solution you'd like

In TranslocoConfig, when omitting availableLangs, or setting it to null, I can load any language without restrictions.

Describe alternatives you've considered

We can bite the bullet and maintain the list of supported languages

Additional context

We are migrating from ngx-translate, there we don't need to specify the available languages.

I would like to make a pull request for this feature

Yes 🚀