Filter tasks by archived status

[joshsmith]

Problem

• Add a filter to return tasks based on whether they are archived
• Default for returning tasks is not archived

[begedin]

We should modify Task.Query.list/2 for this.

This introduces an optional filter with a default. What our private do_list functions are doing at the moment is that they apply optional filters without a default.

I'm thinking we should rename them into apply_optional_filters.

In Task.Query

• rename do_list to apply_optional_filters
• add apply_archived_status(query, params), which, if params contain archived, apply the value of archived. If not, they apply the default value of archived: false.
• call this new function from list/2, before or after apply_optional_filters

Also

• add Task.Query tests to ensure this new behavior

Total estimated ~3 hours

[begedin]

Blocked by #1006