Update copies from project to repositories

What does this MR do?

In the section Repository storage inside the Admin panel, we say several times the word projects. Nevertheless, we have more objects that can have repositories now, not only projects.

We need to change the copies and remove any references to projects.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content