Fixed class name
Sections: Add a new page (KeysFromNetworkSection) that will be used for data transmission over network.

This is a temporary scenario which now it isn't even implemented: it should allow to write a message (e.g. key fingerprint) into the text editor and then pressing 'Send' will send the data through network to another isntance of Geysigning (for start should be just a script that displays that data)