GUI integration with history manager

Will be good to have:

[x] Fix bug with impossibility to type a value after adding the first row in properties/headers
[x] Implement small and simple text search by request exchange and routing keys
[x] Implement writing states into the file when closing the application
[x] Implement restoring request history from the file after opening an application
[x] Add opportunity to delete the selected row in kurier/widgets/list_ctrl.py via Backspace / Delete keys
[x] Add opportunity to cancel cell editing in kurier/widgets/list_ctrl.py with Escape key
[x] Add opportunity to cancel searching and clear Search widget input with Escape key

Relrin / kurier