[Enhancement] Assign examples to members

[Hironsan]

This PR introduces the following assignment features:

• Assign an example at a time
• Bulk assign examples to the project members

Assign an example at a time

The project manager can assign examples to members. This allows for flexible assignments but can be stressful if there are many examples.

Bulk assign

The project manager can assign examples to members in bulk. They can select the following:

• Assignment strategy: This controls how to assign examples.
• Weights per member: This controls how many examples the project manager assigns each member.

Result

• The annotators can annotate the assigned examples only.
• The project managers can access all the examples.

Resolved issues

Resolve #948
Resolve #1113
Resolve #1515
Resolve #1993

[kuraga]

@Hironsan , thank you very much!

Are you sure #1113 has been solved by this PR? 7dc58a5 and b4c72af, or which commits did it?

[Hironsan]

I think 7dc58a5 solved the issue.

[kuraga]

I think 7dc58a5 solved the issue.

Is queryset.order_by("assignments__id") really random?

[Hironsan]

I think so.

doccano/backend/examples/models.py

Line 42 in 6387097

id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)

If there are better approach, please let me know.

[kuraga]

Ah, ok.