Use unformatted / raw data for new All Websites dashboard

[sgiehl]

Description:

This PR contains the following changes:

• The JavaScript NumberFormatter class has been migrated to vue.js
• The getFormattedEvolution javascript method has been migrated to the new NumberFormatter
• The MultiSites API method have been improved/fixed to
  • Return proper metric names for previous period (e.g. previous_hits instead of previous_Actions_hits)
  • Return metrics for previous period in totals
  • Removed mock data API method
• The new MultiSites Dashboard UI has been improved to
  • Use the normal API instead of mock
  • Request API data unformatted
  • Calculate evolutions based on current and previous data (instead of using the evolution metrics provided by API)
  • Format all numbers correctly before displaying the using the new NumberFormatter component
• Improved / Updated / Added tests

Note: There is still a lot code, that needs some more refactoring. We should aim to do that as part of removing the old all websites dashboard.

Review

• Functional review done
• Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• Security review done
• Wording review done
• Code review done
• Tests were added if useful/possible
• Reviewed for breaking changes
• Developer changelog updated if needed
• Documentation added if needed
• Existing documentation updated if needed