Add widget examples

[srtena]

Adds new examples that leverage the new Widgets feature plus all the utils in carto-api-client

The examples are meant to be a very raw, simple, starting point for anyone that wants to learn how CARTO + deck.gl work, and in particular, for anyone that wants to learn how to build interactive, synced widgets with CARTO + deck.gl.

Scope:

• [x] Hello world with widgets:
  • the goal with this one is to provide a more general example using multiple, interconnected widgets
• [x] Formula
• [x] Categories
• [x] Histogram
• [x] Range
• [x] ScatterPlot
• [x] TimeSeries
• [x] Table
• [x] Other charts

Before publishing

• [x] Update carto-api-client versions
• [x] Check readmes
• [x] Check links
• [x] Check Stackblitz buttons
• [x] Cleanup unused code and css

[srtena]

CR? This looks ready to merge if you agree @donmccurdy 🥹 🚀

[donmccurdy]

LGTM! 👏🏻

[felixpalmer]

Amazing job @srtena !!! ❤️