Updated positioning of copy file path button in diffs

## What does this MR do?

Updated the positioning of the copy file path button in diffs.

## Screenshots (if relevant)

![Screen_Shot_2016-10-31_at_16.53.24](/uploads/53de39ce550855f86b90d2d9fc227f95/Screen_Shot_2016-10-31_at_16.53.24.png)

## What are the relevant issue numbers?

Closes #23591

See merge request !7203