Feature: Support for display history

[Nillissen]

Add support for a display history of shown Frames/Forms and include a Back method. That way we can add Back button to our UI and have the Stand move backwards through the history of displayed Frames.

[andrea-magni]

Hi, please have a look at FMXER (https://github.com/andrea-magni/FMXER).
It is a project based on TFrameStand/TFormStand and also provides a navigational support across views (routes).

TFrameStand/TFormStand keep track of active frames/forms but that is far from a true application-wise navigational architecture.

Sincerely