feat(SecurityGroup):added method to add security grouo to server

[dweinholz]

Try to fulfill the following points before the Pull Request is merged:

• The PR is reviewed by one of the team members.
• If a linting PR exists, it must be merged before this PR is allowed to be merged.
• If the PR is merged in the master then a release should be be made.
• If the new code is readable, if not it should be well commented

For releases only:

• If the review of this PR is approved and the PR is followed by a release then the .env file
  in the cloud-portal repo should also be updated.
• If you are making a release then please sum up the changes since the last release on the release page using the clog tool with clog -F

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
simple_vm_client
VirtualMachineHandler.py	170	2	2	99%
__init__.py	1	0	100%
test_virtualmachinehandler.py	299	0	100%
simple_vm_client/bibigrid_connector
__init__.py	0	0	100%
bibigrid_connector.py	116	4	4	97%
test_bibigrid_connector.py	173	0	100%
simple_vm_client/forc_connector
__init__.py	0	0	100%
forc_connector.py	255	4	4	98%
simple_vm_client/forc_connector/playbook
__init__.py	0	0	100%
playbook.py	191	0	100%
test_playbook.py	380	0	100%
simple_vm_client/forc_connector/template
__init__.py	0	0	100%
template.py	195	1	1	99%
simple_vm_client/openstack_connector
__init__.py	0	0	100%
openstack_connector.py	753	14	14	98%
simple_vm_client/scripts
__init__.py	0	0	100%
simple_vm_client/util
__init__.py	0	0	100%
state_enums.py	69	0	100%
test_thrift_converter.py	170	0	100%
thrift_converter.py	63	0	100%
TOTAL	2835	25	99%

Tests	Skipped	Failures	Errors	Time
300	0 💤	1 ❌	0 🔥	4.323s ⏱️