Secure security group rules (#43)

* Added the outbound rule to the EmptySecurityGroup to allow it to access Canvas Data API.

* Added the egress rules for DatabaseClientSecurityGroups to allow access to the Internet for Canvas Data API and the RDS Aurora Cluster.

* Removed the previous DatabaseClientSGToEgress5439 egress rule, and created two separate Egress rule for the conditions CreateDatabaseSecurityGroup and ExistingDatabaseSecurityGroup.

* Renamed EmptySecurityGroup to ListTablesFunctionSecurityGroup for better readability. Added GroupNames for security groups.

* Removed the GroupName attribute from security groups. Added the Name Tag and value for the security group names.

* Updated the GroupDescription for ListTablesFunctionSecurityGroup.

* Added the GroupName attribute for the security groups.

Author: PyMedic