Provide get_color methods in VTE
At the moment VTE only provides methods for setting colors, it does not provide methods for getting the colors currently in use. If the user changes colors using escape sequences, the wrapping terminal emulator has no knowledge of this.
This is normally not a concern, however with the new capability where the wrapping emulator can draw the background itself instead of VTE this means the wrong color could be used. It would be great if VTE had corresponding get_color methods to match the current set_color methods.
See https://github.com/gnunn1/tilix/issues/1455 for the original reported issue.