Prioritize vaccination sites with website registration

[kevinjcliao]

When visiting vaxx.tw, you notice that some vaccination sites have website registration and some do not.

The goal of this PR is to sort the vaccination sites, showing those with website registration first.

[chunyenHuang]

@kevinjcliao @SeanGau Do we need to provide other sorting/filtering options like

• lastModified
• name
• governmentPaidAvailability
• selfPaidAvailability