[Accessibility] Handed user (Left or Right), todo: Tree to right and text-align right or left accordingly

Changed contacts, rename node, corpus code file name to use input field
where enter confirms the edition.

Related to #179

In Home/Public error was thrown: <div> cannot be nested under <p>.

This hides the explicit 'key' prop in App, moves it to the individual
components.

Also, key is generated based on session id and node id.