Map G1 hpc flavors to already present G2 c3 flavors with slightly less
RAM.

Refactor volume migration.

Split the volume migration into 2 separate steps:
- `step1`: create snapshot of source volume
- `step2`: clone snapshot + flatten clone + copy clone to destination
  volume

Introduce a parameter which configures, whether `step2` is done while
the VM is off.

Original (non-default) flow:
1. shutoff source VM
2. perform `step1` + `step2` (originally not split)
3. start source VM
4. ...

New default flow:
1. shutoff source VM
2. perform `step1`
3. start source VM
4. perform `step2`
5. ...

Rationale: There is no reason to keep the source VM off once the
snapshot is created. The VM is started after the migration anyway, so
the source and destination volumes will diverge eventually. The new
default approach aims to reduce the time the VM is off.

Temporary workaround to
https://gitlab.ics.muni.cz/cloud/g1-g2-ostack-cloud-migration/-/jobs/1606061.

When dst network is created (not found), the returned dict does not have
subnets attribute initialized. That may cause issues in later stages,
where we rely on at least one `subnet_id` being present (see
`describe_server_network_connection` function).

Fixed by getting the network from OStack again, after everything has
been created.

See failed pipeline:
- Dst network without subnet
  - https://gitlab.ics.muni.cz/cloud/g1-g2-ostack-cloud-migration/-/jobs/1604037#L72
- Error later in execution
  - https://gitlab.ics.muni.cz/cloud/g1-g2-ostack-cloud-migration/-/jobs/1604037#L146
- Final assertion error
  - https://gitlab.ics.muni.cz/cloud/g1-g2-ostack-cloud-migration/-/jobs/1604037#L164

Re-format all Python code.

Partially fix pylint issues.

Log quotas comparison of source and destination project.

Output a separate log line for each quota based on comparison result:
- `debug` if src_quota == dst_quota
- `warn` if src_quota < dst_quota
- `error` if src_quota > dst_quota

Compare only a predefined set of quotas.

See https://gitlab.ics.muni.cz/cloud/internal-wiki/-/issues/1656.

Break up into 2 functions, simplify control flow, fix asserts, remove
unused functions.

fix: detection of the mapped dst network reworked again (to avoid creation of network when there is mapped one in admin project)

Fixes following tracebacks:
2024-07-09 13:41:13,648 project-migrator INFO F.3 Source server ostack port(s) detected
2024-07-09 13:41:13,648 project-migrator INFO F.3 Source server ostack single (unambiguous) port detected
Traceback (most recent call last):
  File "/builds/cloud/g1-g2-ostack-cloud-migration/ci/project-migrator.py", line 402, in <module>
    sys.exit(main(ARGS))
  File "/builds/cloud/g1-g2-ostack-cloud-migration/ci/project-migrator.py", line 173, in main
    olib.get_or_create_dst_server_networking(args,
  File "/builds/cloud/g1-g2-ostack-cloud-migration/ci/olib.py", line 265, in get_or_create_dst_server_networking
    i_dst_network, _, _ = create_destination_networking(args,
  File "/builds/cloud/g1-g2-ostack-cloud-migration/ci/olib.py", line 113, in create_destination_networking
    src_subnets = [ src_ostack_conn.network.find_subnet(i_src_subnet_id) for i_src_subnet_id in src_network.subnet_ids ]
AttributeError: 'NoneType' object has no attribute 'subnet_ids'

Depends on https://gitlab.ics.muni.cz/cloud/g2/prod-brno-cloud-entities/-/merge_requests/58.

This patch fixes following problem:
2024-07-02 12:29:49,117 project-migrator INFO F.9 Destination OpenStack server keypair exists (vscht)
Traceback (most recent call last):
  File "/home/freznicek/prjs/muni/sources/gitlab.ics.muni.cz/g1-g2-ostack-cloud-migration.git/ci/./project-migrator.py", line 389, in <module>
    sys.exit(main(ARGS))
             ^^^^^^^^^^
  File "/home/freznicek/prjs/muni/sources/gitlab.ics.muni.cz/g1-g2-ostack-cloud-migration.git/ci/./project-migrator.py", line 190, in main
    olib.get_or_create_dst_server_security_groups(args,
  File "/home/freznicek/prjs/muni/sources/gitlab.ics.muni.cz/g1-g2-ostack-cloud-migration.git/ci/olib.py", line 452, in get_or_create_dst_server_security_groups
    for i_src_server_security_group_name in {i_sg['name'] for i_sg in src_server.security_groups}:
                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: 'NoneType' object is not iterable
[freznicek@lenovo-t14 ci 1]$