Incorporate Tenant timezone into emails

The dates and times shown in the emails should incorporate the tenant timezone for that tenant.

The assumption is that most users will be in the timezone of their tenant. Many users will not be familiar with the timezone notation, so we can just show the date and time for now. At least it should be an improvement over the current functionality.

If user feedback shows that not having the timezone information is confusing, we can consider adding it back in.