Budget to Transaction list

This commit changes some basic things:

1. Import Stage is now not a real state. there is a new CurrentSource
property that says what is the state of the Transaction list panel. DB,
Import or (a New state) Event.
this changes all the references to ImportStage property. including in
the Settings panel, to the new (More Intuitive) property of
CurrentSource.
But the more crucial change here is the recombine of the Transaction
Panel initiators into one that deals with all kind of sources.

2. SwitchPanel now checks for a result from the initiators of panels.
This is due the new behavior where a Budget panel can show the
Transaction panel under its own title.
Than, the user can go into the original Transaction panel and interact
with the Database source.
Now, the user can return to the Budget panel with saved state of
Selected BudgetEvent so in-fact the Transaction panel should be shown
instead of the Budget one.
So now, an initiator such as InitiateBudgetEventPage can actually return
False result to signal the SwitchPanel function to cancel the switch (to
the budget panel) so it could call SwitchPanel it self with Transaction
Panel as the destination.