Upgrade to latest MQTT.js

[hardillb]

part of #263

Description

Update mqtt.js and engines section of package.json.

Also had to change the client.connect()` call slightly to get it to work properly.

Related Issue(s)

#263

Checklist

• I have read the contribution guidelines
• Suitable unit/system level tests have been added and they pass
• Documentation has been updated
  • Upgrade instructions
  • Configuration details
  • Concepts
• Changes flowforge.yml?
  • Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production

Labels

• Includes a DB migration? -> add the area:migration label

[hardillb]

These are the changes I needed to make to get #267 to work properly

[Steve-Mcl]

Looks good ben but the whole workaround code can go in the bin now.

I would add a suggestion to save you messing on but its out of the touched code and GH wont let me.

In short, this lot...

        // PROBLEM: ipv6 ws addresses cannot connect
        // INFO: Calling mqtt.connect('http://[::1]:8883') fails with error  ERR_INVALID_URL
        // INFO: Calling mqtt.connect(new URL('http://[::1]:8883')) fails because `connect` only accepts a `string` or `url.parse` object
        // INFO: Calling mqtt.connect(url.parse('http://[::1]:8883') fails because unlike new URL, url.parse drops the square brackets off hostname
        //       (mqtt.js disassembles and reassembles the url using hostname + port so `ws://[::1]:8883` becomes `ws://::1:8883`)
        // INFO: WS src code uses `new URL` so when `mqtt.js` passes the reassembled IP `http://::1:8883`, it fails with error ERR_INVALID_URL
        // SEE: https://github.com/mqttjs/MQTT.js/issues/1569
        // eslint-disable-next-line n/no-deprecated-api
        const brokerURL = url.parse(this.config.brokerURL)
        const _url = new URL(this.config.brokerURL)
        brokerURL.hostname = _url.hostname

simply becomes ...

        const brokerURL = new URL(this.config.brokerURL)

[Steve-Mcl]

Approved...

MQTT JS v5.10 is now released - do we want to bump to latest or leave as is here?

Will let you decide to bump or merge :)

[hardillb]

Not merging until we decide the release strategy for this, as I think we need to tag a NodeJS v14 support branch

[hardillb]

Just a moment, rebasing to pick up the package-lock.json