Prompt user of saved map state

[7malikk]

Please describe the desired behavior.
Describe the solution you'd like.
Include a prompt message informing the user that a JSON file has been detected in the response of supplied URL and also inquiring if the user would like to recover the saved map.

Place a filter for JSON files here
If items in each JSON file meet these requirements:

jsonFile.hasOwnProperty('nodes')  && jsonFile.nodes.length > 0 === true
jsonFile.hasOwnProperty('src') === true

If the files meet these requirements then trigger the aforementioned prompt

Upon the close of the prompt, invoke the map reconstruction

[7malikk]

@jywarren Hello, per our discussion yesterday here is an issue on a part of it.