Remove is-browser.ts detection util in favor of config option

[olso-nordsec]

Is your feature request related to a problem? Please describe.

• It seems this detection adds unnecessary complexity
• There have been https://github.com/mqttjs/MQTT.js/commits/main/src/lib/is-browser.ts quite a few fixes for it, there is lot of edge cases
• Chrome extension detection is bit flaky (some of this pain has been alleviated by https://github.com/mqttjs/MQTT.js/pull/1818)
• https://github.com/mqttjs/MQTT.js/issues/1709

Describe the solution you'd like Configurable by required option

mqtt.connect(credentials.endpoint, {
  environment: 'browser', // 'react-native' 'electron' 'node'
})

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered.

Additional context Add any other context or screenshots about the feature request here.

[robertsLando]

@olso-nordsec problem is that actually we also need that in order to know which modules to load and which not (as some wouldn't work on browser). For the other points in code I think your solution could work but we firstly should define how to fix this. Maybe there could be a way by using esbuild

If you have something in mind feel free to open a PR

Ref:

https://github.com/mqttjs/MQTT.js/blob/cd0b044b89e8413e99e055529d523eac6d4ddcd4/src/lib/connect/index.ts#L21-L33