Added code to attempt to revert back to the same frame that user was on prior to setFrame reload.

Make screen to revert to Frame 0 if the originally displayed frame is no longer there.

Inserted boolean holdPosition into setFrames to indicate the requirement to stay on the same frame ( if =true) or else it will switch to new frame .
Only Screen::handleStatusUpdate calls with setFrame(true). ( For Node Updates)
All other types of updates call as before setFrame(), so it will change focus as needed.

Collaboration on meshtastic#4043

…frame-focus

…frame-focus

…frame-focus

Previously, this was calling Screen::setFrames at unexpected times

Notify only when relevant. Currently: only to handle remove_nodenum.

This is done internally by calling MeshModule::requestFocus()
Easier this way, insteady of passing the info in the UIFrameEvent:
* Modules don't always know whether they should be focussed until after the UIFrameEvent has been raised, in dramFrame
* Don't have to pass reference to module instance as parameter though several methods

Previously, it had its own basic implementation of this.

…frame-focus