[Vue] migrate piwik-widget and related directives #18429

Description:

This PR is based off of #18428.

Changes:

• Migrate piwik-widget-bydimension-container directive.
• Migrate piwik-widget-container directive.
• Migrate piwik-widget directive.
• Do not show ajax request failures if not logged in.
• Remove SiteSelector adapter hack since it is fixed by the Field adapter ng model binding + remove selectedSite state since it's not used anymore.
• Create v-tooltips directive to encapsulate jquery UI tooltips usage. Useful since we want to remove it when an element disappears, not the component.
• Add Widgets store for handling results of widgetsHelper.getAvailableWidgets().

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

UI tests should be passing for this PR

@sgiehl I'll fix these in the other branches individually. I will have limited availability however for the next couple weeks, so it's ok to do one Vue review a day (if there's a PR to review) in my opinion. I won't have time to get to everything.