Description of the new feature/enhancement

Currently, when I have a tab opened in terminal, it uses background image of specific profile. If I add more split panes from the same profile or from different ones, background image tries to fit pane for specific profile.

So it looks like this for single pane in tab:

And like this for multiple panes in tab:

I'd like to have single background image for tab, even if it has multiple panes (image would be just "cut" by panes borders). So I'd like to have only one background image like in first screenshot, but still use many panes, like in second.

For this scenario, background images of specific profiles would be ignored or only background image of first pane opened in tab would be taken into consideration and shown.

Lots of other configuration options which control how terminal looks like could be also configurable per tab.