Issued zone for instances from instances.list()

[fredriksvendsen]

Problem

Instances from InstancesAPI.list() are always parsed in the default zone; UTC.

We don't necessarily know the curve's instance_issued_timezone because the response does not include curve metadata (only instance), and the curve input might be the curve name which is a simple string.

Possible solutions

We can parse issued in the correct zone if a curve object is provided. Either the user provides the curve, or we do an additional request to eq.metadata.curves.

Another solution could be to parse in the curve's instance zone only when a curve object is provided by the user.

[fredriksvendsen]

Solution: don't localize with a timezone if we don't have curve metadata. Just use a datetime with offset.