Allow disabling of middle-click to close a tab.

[mark-edgington]

Description of the new feature

When trying to select a tab by left-clicking, if one accidentally middle-clicks, the unfortunate consequence is that the entire shell history and context is lost due to its tab being closed. It would be great if there were a configuration option to disable this middle-click-to-close functionality.

Proposed technical implementation details

No response

[johnyoodev]

May I take this on?

[DHowett]

I think this will be better served by #6549 and more intelligent close prompt detection, but in the meantime... does toggling read-only mode help? It should prevent you from closing a "locked" tab or a window containing a locked tab. Unfortunately it will also display a warning when you try to type into the tab.