Support dynamic querying & add a select to toggle between schema versions

[jessicamcinchak]

The docs are currently configured to query a single schema based on static version number: https://github.com/theopensystemslab/digital-planning-data-schemas-docs/blob/main/api/useQuerySchemas.ts

For more flexibility, we want to:

• Instead fetch "@next" and "@latest" versions so we don't have to regularly update this repo (related to Smooth out CI build process for @next & latest /dist branch folders digital-planning-data-schemas#242)
• Allow the front-end user to select between various schemas - "application", "preApplication", "prototypeApplication" etc - and versions within in them to compare & visualise changes ("@next" & "@latest" to start, but ideally all published dist branch versions??)
  • Still only rendering one schema viewer at a time, but with header-level toggle/select dropdown to manage state/fetch appropriately