[database] - Add datasnapshot interface and transaction prototype
[database] - Add datasnapshot interface and transaction prototype

EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase,EddyVerbruggen/nativescript-plugin-firebase