Display a check button even for annotators

[youichiro]

Issue

#280

What this PR do

• display check button for all roles including annotator.
  • when the check button is clicked, confirm API is called and an example_state record is created.
• separate confirmation status for each user.
  • when a project.collaborative_annotation is True, share status by each role.

Before

• Check button was hidden when user is annotator.
• The same status was shared by approver and admin.

After

When project.collaborative_annotation is False

• Each user has an independent example state.

When project.collaborative_annotation is True

• Each role has an example state.

Screenshot

Check button is displayed even if user is annotator.

Next action idea

• Display the example status in the annotation screen or dataset page.
  • Approver should want to know the example annotation is completed.
• Fix filter results
  • If Done is selected, examples confirmed by annotator will be filtered.
• Change graph displayed on the statistics page.
  • Delete the current completed/Incompleted graph.
  • Added graphs of completed/uncompleted annotations and completed/uncompleted approvals.