Convert cell data viewer modal into cell data editor #781
Description
The goal here is to provide a more convenient tool for editing cells with large amounts of data. JSON cells are good example for such use case.
Basically cell data modal should have a read-only flag. If set to True it will behave like the current cell data viewer.
Otherwise this modal should allow to edit cell data; in this setup it should have an apply or save button that will set cell data with the current state of the editor.
Potential issues:
not every type of cell data could be easily edited in that modal. Binary data is a good example.
cell data modal supports code formatting which is useful for viewing data but may be undesired for data edit cases. Research if it is possible to format cell data for easier editing but save the only the changes made by the user, ignoring auto-formatting changes.