InputNote: Use button for submitting text.

Wrestled with the QtQuick Layouts for a while. The TextArea vas not visible
unless the Layout.minumumHeight attached property was set.
InputNote: Add noop FileDialog.
InputNote: Connect Buttons to Actions.
Move cpp and qml files to their own subdirs.

Follows the layout used in the Qt examples.
InputNote: Use styles for the buttons.
Add skeletal Adapter class.

Will be used for handling all application logic (I've decided to keep the Qml
files clean).
transform.py: Add good-enough parser.

The parser is messy, since it doesn't separate the tokenizer task from the
parser task. But it translates my text notes correctly and I will only use it
once, so I leave it as-is.
Connect signal from qml to c++ adapter.