feat: handle route prefix for Next and Nuxt

[Shywim]

Q	A
Branch?	main
Tickets	#310 #284
License	MIT
Doc PR

This adds support for route_prefix for Next and Nuxt. Directories for each segment are created for the pages, e.g. foo/bar/entity will create pages/foo/bar/entity/index.js and so on for every template.

This fixes #284 and #310

This also comes with a fix for the Next template which didn't work out the box due to the API response being parsed twice (res.json() followed by res.text()) in dataAccess.ts