Add client filtering of conversation part types for authorized users

# Problem

Add the ability for authorized users (admin) to filter by conversation part type.

This is currently blocked by 1638 and 1689.

# Add client-filtering of parts based on authorizaton
Wrap non-comment parts in the conversation thread under a `{{#if canAdminister project}}` helper, to hide non-comment parts from users who aren't admins on project.

## Add integration tests to support this change
Render a thread with one of each supported part type, register a fake project ability with `canAdminister: true`
Render a thread with one of each supported part type ,register a fake project ability with `canAdminister: false`, see if just the comment part is rendered
See `tests/integration/components/task-assignment-test.js` on how to register a fake ability

## References #1636 #1638, #1689

Progress on: #1597

Revise primeiro os bloqueios #1638 e #1689 e, em seguida, use tests/integration/components/task-assignment-test.js como referência para registrar uma fake ability. Adicione cobertura de integração para uma thread contendo cada tipo de part compatível, com canAdminister true e false; está concluído quando os admins veem todas as parts, enquanto os não admins veem apenas os comentários.

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