Correctly check existence of target directory in `copy_recursive` function

[georgemunyoro]

Please see this comment and the one below it explaining the problem and my solution to it.

Release Notes:

• Fixed issue where copy-paste for folders was not working in the project panel (#6778).

[szepeviktor]

There is an extra space in the link text in "Release Notes".

[georgemunyoro]

Thank you for the fix. Let's add a test in the same module so this functionality does not regress later, the existing test could serve as an example.

Added the test, it ensures folders are copied recursively and are renamed when there is an existing entity with the same name.