Configurable timezones per user

Is your feature request related to a problem? Please describe.
Decidim is configured with a particular timezone and all of its actions, comments and specially meetings reflect that specific timezone. For Decidim instances that cover a territory or territories that span different timezones this leads to confusion for the end users as neither the interface shows the timezone it is configured in on things such as meetings, and for actions, if I export a meetup to my calendar it won't bring in the meeting timezone information so I never get the proper TZ for it.

Describe the solution you'd like
The best solution, IMO, would be to allow users to configure their own TZ, either within the sign up process, or through the user account screen, and have everything on the interface modify to that timezone. An alternative, minimum solution, would be to disclose the TZ whenever timestamps are referenced and have the .ical export to grab the tz so that any meetings I export get the proper time.

Describe alternatives you've considered
Cry. j/k. I see this problem is being dealt with in this issue. This feature request is only to discuss if the first proposal of having time-zone per users can be considered.

Additional context
The dynamic in metadecidim is a great example since we are a global community, we are always operating in different timezones. You can take a look at conversations in our chat for more info

Does this issue could impact on users private data?
The TZ would be chosen by the user and does not necessarily reflect where they are at... so I believe we are clear here.

Funded by
Not yet but if it need be, I can help build an estimate and find a way to procure for it. This feature I don't need it for myself or a client but as a feature I think would be useful for the overall product.