Merge import modal into overview's Import section

Description

Closes issues: LA-1270 Related issues:

Notes to reviewer

• Removed warning when annotation service is down. Polling that resource has caused some issues in the past.
• ImportData in model is not refactored to use Cerebral, it's still calling AngularJS resources.
• If the submission fails in user input mode, the form is still cleared. Reason is that the state is separated in the component and Cerebral, and the component doesn't know the result of the submission. If we'd like to move all state to Cerebral, we'll need to refactor ImportData.
• e2e tests are coming in !302 (merged)

Type of change

Application (affects UI or general functionality):

• New feature
• Bug fix
• Improvement

Ops / admin / CI related only (not impacting users):

• New feature
• Bug fix
• Improvement

Tests

General

• Tests have been added that prove my fix is effective or that my feature works
• Related tests have been modified/removed

Hypothesis testing:

• Soak testing has been done
• Distribution between positive / negative cases has been checked

Database

• Includes changes to database schema
• Includes necessary database migrations

Configuration

• Includes changes to configuration
• Includes configuration migration instructions in documentation

Merge checklist

• Self-review of code performed
• Feature review against specification (if applicable)
• Need for documentation has been evaluated and, if necessary, updated
• Code and implementation is reviewed by other core developer (all changes, inc. changes based on initial review)