Typing improvements for `io` and fixes for `websocketclient`, and a few others

[cmidgley]

This is the work I've done to date with io focused on making websocketclient to be reliable and strongly typed with TypeScript. It's a fairly substantial set of changes, mostly in the .d.ts files but some implementation (especially websocketclient).

Type changes:

• New types for embedded:io/socket/tcp/tls, embedded:network/http/server, embedded:network/http/server/options/webpage, embedded:network/https/server/options/websocket, and embedded:network/websocket/client
• Improvements to types embedded:io/socket/listener, embedded:io/socket/tcp, embedded:io/socket/udp, embedded:network/dns/resolver/udp, embedded:network/http/client, embedded:provider/builtin
• Added Device (for global variable device) into global types to eliminate requirement for import
• Extend the global namespace for Device for when imports of extended modules are used (support for embedded:network/http/server, embedded:network/websocket/client)

Implementation changes:

• Bug fixes/improvements for websocketclient:
  • Implement error property via onError(error: string) (new feature)
  • Fix issue where control message payloads were not being decoded with the mask (data corruption)
  • Fix an issue where masks were used on both client and server (spec requires masking on client to server only)
  • Fixed issue where fragmented reads used an improper mask (data corruption)
• Fix a bug in websocket where using attached sockets would fail (reported in #1428)
• Add common HTTP status codes to httpserver on the HTTP/1.1 <status> <code> header
• Added options feature to embedded:network/http/server/options/webpage to support .contentType and .status.

I typed everything based on the current implementation and not ECMA-419 (many modules are inconsistent with the published 2nd edition of the spec).

[cmidgley]

Fixes are in place. Let me know what else you find..