[Feature] JSON db as a data source

## Summary

As a user I should be able to query data directly from an uploaded JSON file in the datasource and use it in a widget.

## Motivation

Sometime is want to show static dropdown options for which connecting to a an actual DB is an overkill. I should be able to instead upload a JSON file with the required object and query it through a widget.

## Additional Context

Ex: I have an input which takes in phone and I need the user to select the country code. So while showing options I wish to show the country code with the country name and flag. To do this i can simple use a static JSON object [like this](https://gist.github.com/somangshu/93c83900714d14fe86502be6c48738c7). Being able to store this object as a datasource and perform simple queries over it can be really helpful.