Mqtt5 General Avalibility

What's Changed

• Add shared subscriptions test by @sfod in #509
• Hardcoded napi_no_external_buffers_allowed value for Node 21 and below by @xiazhvera in #508
• Fix some canary issues by @bretambrose in #511
• Mqtt5 ga by @bretambrose in #510
• Mqtt5 topic aliasing browser by @bretambrose in #505
• Conditionally uri encode custom auth signature values by @bretambrose in #513
• Don't let browser choose port in 311 implementation by @bretambrose in #514
• Mqtt5 General Availability by @xiazhvera in #518

Full Changelog: v1.19.1...v1.20.0