Corrections to Spanish language file and Catalan language file added

[KikoVivesUA]

We needed Catalan language to be available in Opencast-Studio so we added the corresponding file, compile Studio, and tested it. While translating the Catalan file, also noticed some minor fixes that needed to be made to the Spanish language file.
So:

• Added the Catalan language file and included it in the drop-down menu.
• implemented minor corrections to the Spanish language file.

[LukasKalbertodt]

Hi, thanks for the pull request! That sounds like a reasonable addition. I will try to find some Spanish and/or Catalan speakers to review this.

Just one technical remark: why are there changes in package-lock.json in this PR? Are those required? If not, it would be great if you could remove those changes to keep this PR atomic (just about languages).

[turro]

I've reviewed all the changes in catalan and spanish and they are ok. I've not finished the review in order to make a final decision on package-lock.json

[LukasKalbertodt]

Thanks Carlos for the language review! The package-lock changes are also gone, so this is good to go! Thanks again!

Regarding release: I plan on landing a couple minor things soon and then I will make a release, also updating it in Opencast.