Edit form with Bootstrap 4

[tyddynonn]

The layout of the Edit form seems to be broken when using Bootstrap 4 as the GUI

• Submit & Cancel buttons don't stay in the same row as the screen is resized
• Data Nav buttons don't have the icon centered in the button

Workaround is to remove the Icon from the Submit/Cancel buttons using the saveicon and closeicon options.

There doesn't seem to be an option to adjust or remove the Nav buttons on the form. And it would be nice to be able to add Bootstrap Classes (e.g. btn-sm) to the Form buttons