feat(annotation): simplify task creation and streamline sync workflow

[o0Shark0o]

• Restrict annotation tasks to a single dataset while allowing multi-data selection
• Unify sync mechanism by removing forward/backward distinction and only syncing results back to the source dataset
• Simplify task actions by keeping primary actions (sync, edit) and moving low-frequency actions to a secondary menu
• Store auto-annotation results directly in the source dataset without creating additional image datasets
• Enable automatic sync of auto-annotation results to Label Studio upon completion
• Refactor annotation task creation UI to improve configuration clarity and data selection flow