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

Added a default quick installation section, and passed the custom installation README to another subsection. Moved the vxlan configuration to an external md file.

- Added health checks in the containers to enable readiness and liveness probes

- Implemented Probes and initContainers so the installation follows a specific order without having to manage it.

Implemented readinessProbe in l2sm-controller Deployment and added initContainers in l2sm-operator Deployment to ensure proper synchronization with l2sm-controller pod status before starting.

This change ensures that l2sm-operator does not start until l2sm-controller pod is in the Running state.

More typo fixes in installation guide

Fixed typo when referencing directory, custom_installation/ -> custom-installation/

Fixed loop  that occured when two bridges joined together and the switch, forming a loop that would take all the CPU usage from process systemd-networkd