Support custom DONE statuses in tasks

[dr-rsls]

Problem

Dataview currently treats only [x] checkboxes as completed. Custom statuses (e.g. [T], [!]), even when marked as DONE in the Tasks plugin, appear as checked = true but completed = false. This makes Dataview queries inaccurate for users of custom task statuses.

Proposed solution

Enhance task metadata handling in Dataview:

1. Respect status types dynamically
   • If richer status definitions are available (e.g. from the Tasks plugin), Dataview should use them automatically.
   • Any status of type DONE should map to completed = true.
   • Other types (TODO, IN_PROGRESS, CANCELLED, etc.) could be exposed in a new field, e.g. statusType.

Existing work around

Dataview currently exposes the raw status symbol with the property 'status'
- Provides the exact character inside [ ] (e.g. "x", "T", "!").
- This lets users interpret custom tokens themselves in queries.

Example

[T] is defined in the Task plugin as a custom status 'DONE'.

- [T] Finish report
- [x] Send invoice

Current in Dataview:

For [T]: checked = true, status = "T", completed = false,
For [x]: checked = true, status = "x", completed = true

Proposed:

For [T]: checked = true, status = "T", statusType = "DONE", completed = true
For [x]: checked = true, status = "x", statusType = "DONE", completed = true