UI/UX for empty state when selected contents have different units

[Maren-SSB]

This issue is an extension of #113.

The empty state design and final text are not finalized yet and will be defined as part of this task.

New empty state message

• English:
  • Heading: The line chart cannot be displayed
  • Body: Different units are selected in the filter. These cannot be displayed in the same line chart.
• Norwegian:
  • Heading: Linjediagrammet kan ikke vises
  • Body: Det er valgt ulike måleenheter i filteret. Disse kan ikke vises i samme linjediagram.
• Swedish:
  • Heading: TBA
  • Body: TBA

Illustration

• Not sure yet ...

Minor change in the EmptyState component

• Border radius changed from border-radius-small to border-radius-medium

Acceptance criteria

• An empty state is shown when selected contents have different units.
• The empty state explains why the chart cannot be displayed.
• The empty state provides guidance on how to resolve the issue.
• The same empty state is shown regardless of whether the user changes selections in an existing chart or switches from table view to chart view.