Enable selecting text

[stuartleeks]

I used to be able to use the mouse to highlight sections of the terminal output (typically in the content view) to copy to the clipboard.

I am no longer able to do this (I'm guessing it is related to #339?) and have to use the Copy Content action to copy the full content, and then paste that somewhere to find the text I want.

[lawrencegripper]

Oh dear, that wasn't intended. Not sure if I'm happy to sacrifice that feature to enable clicking.

Flagging this as a bug to look at.

[lawrencegripper]

Taking a look at this, if it's not easily fixable I'll put the mouse support behind an option and default to not having it on.

[lawrencegripper]

This is semi-resolved by #347 but keeping this open as a nicer solution would be to support mouse clicking and text selection at the same time.