Hard-coded language string

[volodymyrdovhan]

Hello,

I noticed hard-coded language strings in some files. All user-facing strings should be defined in the language file and displayed using the get_string() function.
https://moodledev.io/general/community/plugincontribution/checklist#strings

[francopantoja]

Hi

Updated lang in the differents plugin languages, EN, ES, CA, GL, EU

Regards