This moves the heuristic to exist only once and avoids duplicating it.
Additionally this increases the checks accuracy.
Last, the 'moved' price in desktop now is white to indicate it is
not a balance change.
The ImportWalletPage now loads the QML provided by the module,
exposed via the metadata of modules.
The module gets just a blockheight property and then will do
"its thing".
This will either instantly close when there is nothing to do
and continue instantly to the actual import.
Or the module will check the server, initiate download and when
all is setup and done THEN close the popup and continue with
the actual import.
tomFlowee