sqlite3 WASM Demo Page Index

Below is the list of demo pages for the sqlite3 WASM builds. The intent is that this page be run using the functional equivalent of:

>     althttpd -enable-sab -page index.html

and the individual pages be started in their own tab. Warnings and Caveats:

- Some of these pages require that the web server emit the so-called COOP and COEP headers. althttpd requires the `-enable-sab` flag for that.

The tests and demos...

- Core-most tests
  - tester1: Core unit and regression tests for the various APIs and surrounding utility code.
  - tester1-worker: same thing but running in a Worker.
- Higher-level apps and demos...
  - demo-123 provides a no-nonsense example of adding sqlite3 support to a web page in the UI thread.
  - demo-123-worker is the same as `demo-123` but loads and runs sqlite3 from a Worker thread.
  - demo-jsstorage: very basic demo of using the key-value VFS for storing a persistent db in JS `localStorage` or `sessionStorage`.
  - demo-worker1: Worker-based wrapper of the OO API #1. Its Promise-based wrapper is significantly easier to use, however.
  - demo-worker1-promiser: a demo of the Promise-based wrapper of the Worker1 API.