[Feat] Useful new-user infobar gone at second launch of GUI

[neteler]

Is your feature request related to a problem? Please describe.

The GRASS GIS 8 GUI shows a very helpful infobar at initial startup:

This is not shown any more at a second or later start of GRASS GIS 8.

Example: a new user starts GRASS GIS, switches to single-window-GUI-mode and restarts the GUI. Then the infobar is gone.

Describe the solution you'd like

Always show the infobar unless the user clicks on "no longer show infobar" (or simply "hide" or likewise).

Describe alternatives you've considered

Have a [ ] setting in the preferences to enable/disable it.