Add beamtime assignment functionality for dewars and pucks

Implemented API endpoints and frontend logic to assign/unassign beamtime to dewars and pucks. Enhanced schemas, models, and styles while refactoring related frontend components for better user experience and data handling.

backend/app/schemas.py

@@ -568,6 +568,7 @@ class DewarBase(BaseModel):
     tracking_number: str
     number_of_pucks: Optional[int] = None
     number_of_samples: Optional[int] = None
+    created_at: Optional[datetime] = None
     status: str
     contact_id: Optional[int]
     return_address_id: Optional[int]
@@ -584,6 +585,7 @@ class DewarCreate(DewarBase):
 class Dewar(DewarBase):
     id: int
     pgroups: str
+    created_at: Optional[datetime] = None
     shipment_id: Optional[int]
     contact: Optional[Contact]
     return_address: Optional[Address]
@@ -772,6 +774,18 @@ class PuckWithTellPosition(BaseModel):
         from_attributes = True
 
 
+class PuckResponse(BaseModel):
+    id: int
+    puck_name: str
+
+
+class DewarWithPucksResponse(BaseModel):
+    id: int
+    dewar_name: str
+    created_at: datetime
+    pucks: List[PuckResponse]
+
+
 class Beamtime(BaseModel):
     id: int
     pgroups: str