Template field edit popup Enhancement - Cancel option

When editing template fields using either the default or custom popup, would be great to see a “cancel” button.  The cancel button would revert any changes made to any fields in the popup only, not the entire model.  

Currently, from a UX perspective, since there is no cancel button, the user will likely click the “X” on the popup when they want to dismiss changes and instinctively they will think that they cancelled any changes they made on that screen.  However, current functionality persists any changes they made.  By adding a cancel button and having the “X” result in a cancel, users will have a clear option for reverting changes made on the popup while still maintaining any other changes they have made on the main page.