Add concept of a session.
Add concept of a session.

Thisis the translated State from the data base into a job session.

At the moment a session only has a UUID.

Sessions are referanced by Enviroments so must be created first.

Signed-off-by: Owen Synge <d1d4fd964cef7d0e7c6a7c6237ad92c9cf2de236@jaysnest.de>

osynge/whenenv-rust,osynge/whenenv-rust