fixed bug where the database wasnt corretly called when deleting a pod

fixed bug where multus was called before the operator, not allowing the pod to receive an ip address assigned

Following discussions with the SWM team, static ip address implementation was required. This is done now by specifying with the pod an optional ip address field. If no ip is defined, a default ipv6 will be used

Updated the operator, fixing a bug with the database connection, where if a network is deleted and still has pods, it would break it

Updated l2sm database schema and operator to go along with it. Now there are more constraints in the database and errors are handled accordingly, so the application is more robust against errors

Removed criptography dependency in the l2sm operator, as it has security risks attached to it and it's no longer needed

Following the python guidelines of usage, the operator's Dockerfile has been updated, to use a requirements.txt outside the dockerfile.

Identation fixes

The source code directory has been moved from ./build to ./src.

This change was made to improve project organization and follow best practices.