Allow JSON blobs to be toggled to text inputs in vSLAM Sandbox

[vadixidav]

Currently, the reconstruction settings and the camera calibration will be passed as JSON blobs. This is good for being able to share settings with other users, but it may be confusing. This task is to be able to toggle between JSON and text input mode. This would be a radio button selection that allows changing mode. When changing to JSON mode, any text input which has no value entered is not present and is the default value. Likewise, when changing from JSON mode to text input mode, all of the text inputs should be empty where values are not specified in the JSON. This can be achieved using serde_json::Value, which will allow reflection over the JSON.