Auto save notes for every "x" seconds

[SankethBK]

Refer to the documentation of notes schema

Notes bloc is defined in lib/features/notes/presentation/bloc/notes. We need to emit the SaveNote event with a timer of "x" seconds.

Use Timer.periodic to emit this event in lib/features/notes/presentation/pages/note_create_page.dart.

Next step would be to make "x" configurable by taking an input from settings

[droidbg]

@SankethBK Picking this up.