Feature request: Cursor navigation and node selection

What

Be able to enter in a cursor mode, that would allow to navigate the json in RAW using cursors or vim hjkl.

Behaviour

• Press some key (Ctrl+n) for cursor navigation
• Press esc to go back to filter mode
• Press Enter to focus the current json node where the cursor is, and automatically fill the filter mode (See #77)

Optionally: allow select some text pressing shift.