Markup: Administrator Tasks View

[zaychenko-sergei]

Provide a similar view as in Dataset Tasks View, but for administrators and regarding all datasets:

This ticket assumes creating HTML markup, Angular component part, and services with mocked data.
Integrating with actual GraphQL APIs will be done separately.

This page should be accessible only for logged administrator users.

In addition to Dataset Tasks View, Administrator should be able to:

• pause/cancel pausing all updates in the system
• see executor that is/was running the task

Next:

• integrate with API from GraphQL: Administator's view of tasks kamu-cli#281