Create common set of task claiming query filters to be re-used across task claiming, metrics, and health monitoring

[mikecote]

Problem Statement

Each component of Task Manager that looks at the task claiming queue builds a filter from scratch. These filters include tasks with an expired runAt, task types that are recognized, etc. Repeating this code across the components creates room for inconsistency and errors.

Example:

• Overdue task metrics
• Update by query
• Mget query

Proposed Solution

We should find the most common filters for the tasks in queue, share them from a single variable, and reuse them across task claiming, metrics, and health monitoring code.

Definition of Done

• Common filter for tasks in queue created
• Places that can benefit from the common filter are updated

[elasticmachine]

Pinging @elastic/response-ops (Team:ResponseOps)