Read API

[alecandido]

As in #6 an update variant of insert classes is described, a further read variant should be generated.

In particular, the only additional information should be:

• the id
• the ctime

It would be rather useful to return objects, rather than dicts, to the packages directly consuming Qibodb in Python (of course for CLI dicts are perfectly fine).

[alecandido]

This might be partially addressed by 756622c6f2dc8086b9d5d11625e0b5a85e308859 (to be properly tested)