[Course Import/Export] Change "Add to Import Queue" Wording

Problem statement:

As part of the 3-15-25 release, there were updates to the "Copy Course Content" page, changing the original wording on the "Import" button to "Add to Import Queue".

Proposed solution:

While the new wording may seem more technically accurate, it's confusing for end users. Please change the wording back to "Import", instead of "Add to Import Queue" for consistency and to make the experience more straightforward for end users.

User role(s):

admin,instructor