Add Timezone support to ListenBrainz

At current state of the product, listens on ListenBrainz are collected in the UTC instead of their local timestamp, without taking DST in to consideration. Adding timezone preference for users and adding the time zone field in submitted listens will contribute to the analysis and thus provide better user experience. This project aims to add users’ timezone preference paired with their submitted listens. The main work involves making an appropriate table in Postgres to store timezones, designing a react UI page and implementing the corresponding API endpoints. The stretch goal is to include local timestamp in the API, and extract the timezone information from that timestamp to store in the database. The expected outcome is a finished feature ready to be merged into production code.