WebSockets support

[joente]

Description

• Add WebSockets support.
• Change to cmake build system.

https://github.com/orgs/thingsdb/discussions/366

Type of change

• Change build system
• Added feature

How Has This Been Tested?

• Added simple WebSocket test.
• Added simple WebSocket (TLS/SSL) test.
• Duplicate "room" test for events over Secure WebSocket connection.
• Test Linux based builds
• Test MacOS build

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• New and existing unit tests pass locally with my changes