[GFI] Generate Individual Entity Labels

Description:
Add option to generate a label for an individual entity rather than a combined destination label.

Tasks:

• Modify label generation logic to support single-entity mode.
• Exclude other entities going to the same destination when single-entity mode is active.
• Update UI to allow selecting "View Label for Entity".

Acceptance Criteria:

• Labels show only the selected entity and its destination.
• Works consistently across multiple entity types.
• Generated labels render correctly as PDF or print views.

References:

• Related models: Entity
• Review how batch labels are currently generated for adaptation.