Improvements on prepending a plus sign to evolutions #16923

Description:

When showing evolution (comparison or row evolution) we currently prepend a plus sign to positive evolutions.
This PR improves the handling for that and fixes some issues:

• Unifies the handling between comparison mode and row evolution
  Having a change of 0 will now always show +0%, before row evolution didn't prepend the +
• Handle i18n correctly
  Some languages actually don't use a normal + sign for numbers. So use Intl_NumberSymbolPlus instead
• Current comparison doesn't work on PHP8, causing + sign to be always prepended (refs #16897 )

Review

• [ ] Functional review done
• [ ] Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• [ ] Security review done see checklist
• [ ] 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