feat: add timezone to coder_workspace_owner datasource

[ericpaulsen]

add support for querying the user's account and its data via our coder_workspace data source, e.g.

resource "local_file" "timezone" {
  content  = ${data.coder_workspace.me.timezone}
}

[matifali]

I suggest we move provider-related issues to https://github.com/coder/terraform-provider-coder for better organization.

[matifali]

Who ever is going to take this. We should probably do #180 first before adding any major features to the provider.

[matifali]

@johnstcn, this is another related request to expose the timezone I can't think of an example use case for this yet.

[pmareke]

After adding the login_type I would like to give another try to this one, is still open? @matifali do you prefer to do the migration first or go ahead with this one?

Thanks!