Feature Create New file

Divided the ListView operations as ViewOperations, and applied inheretence to ListView and DetailedView.
Moved rename item validation to BaseItem class.
Removed not required imports in some classes.
Implemented the create file operations and added the F7 hotkey and "New
file - F7" button, to call the new create file method.
Still missing the tests.
why if ok != False, basically this means if you were able to introduce the filename correctly you should show an error message, that looks weird i think you need to reformulate your condition here