[4.x] [5.x] Uninstall language process could be improved

[bembelimen]

Steps to reproduce the issue

=> Install a language pack (e.g. during installation)
=> Go to System => Manage => Extensions
=> Filter for languages and then try to uninstall one

=> Error message

Expected result

Better explaination (and a direct link?) that you have to uninstall the package not the language

Actual result

Just a mention to uninstall the package (which is not there, when you filter for "language")

It's not a "programmer bug" but an UX issue

@jonrz and @crystalenka

[MacJoom]

#42602 does not fix this issue

[richard67]

Closing as having a pull request. Please test #42607 . Thanks in advance.