Fix enum serialization when no value is provided

[george-zubrienko]

No description provided.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
esd_services_api_client/arcane
__init__.py	2	2	0%	5–6
_connector.py	59	59	0%	4–158
_models.py	95	95	0%	4–191
esd_services_api_client/beast
_auth.py	27	18	33%	18–19, 27–31, 39–48, 57–63
_connector.py	65	52	20%	29–36, 39–53, 56–79, 90–128, 139–168
_models.py	110	20	82%	41–42, 149–152, 161–169, 179–186, 194–197
esd_services_api_client/boxer
__init__.py	2	2	0%	5–6
_auth.py	25	25	0%	5–52
_connector.py	58	58	0%	4–116
_helpers.py	14	14	0%	3–31
_models.py	32	32	0%	4–97
esd_services_api_client/crystal
_connector.py	64	35	45%	26–40, 49, 63–66, 74, 82, 85, 88, 99–116, 125–134, 144–157, 178
_models.py	33	1	97%	42
TOTAL	654	413	37%

Tests	Skipped	Failures	Errors	Time
9	0 💤	0 ❌	0 🔥	1.117s ⏱️