Refactor LAQN importer to be consistent with other importers

[borkurdotnet]

List of things to change:

• Change package name from lac to laqn
• Change provider from erg.kcl.ac.uk to uk.ac.kcl.erg
• Change subjectType from airQualityControl to airQualitySensor or air-quality-sensor
• Change datasourceId form airQualityControl to airQuality or air-quality
• Make sure all examples and built in models are updated

[ShreejeetaMandal]

Hi @lorenaqendro / @borkurdotnet , Can I be assigned to this?

[lorenaqendro]

@ShreejeetaMandal of course 😊