Modify the source language of a component

**Is your feature request related to a problem? If so, please describe.**

Sometimes when creating a component the source language is incorrectly assigned and we would like to be able to modify it without having to recreate the entire component, considering that the component can have already translations for other languages.

**Describe the solution you'd like**

* Create a component in English (but it should be in German) as a source language
* Add translations for the Spanish language
* Notice that the source language was wrongly assigned, and changing it to German
* Result:
* Spanish translations are still there
* Now it is possible to translate to English
* German translations (if any) are gone because it doesn't make sense to translate to German if the original units were in German already.

**Describe alternatives you've considered**

Recreating component is less comfortable.