TMM 5: bring back ENTER shortcut to save changes

What TMM version are you using?

Version 5.0.10 release, Linux

What is the actual behavior?

The only way to close a dialog window seems to be the OK button (mouse interaction)

What is the expected behavior?

Up to version 4, closing a dialog using the ENTER key was possible. I expected V. 5.x to behave the same way. It's very annoying when editing a bunch of entries (which is almost completely possible by keyboard shortcuts, e.g. "edit movie" -> CTRL+SHIFT+E), you're forced to switch to the mouse just for one single mouseclick...