Rewrite the W3C API on top of Symfony API Platform

[vivienlacourba]

Symfony's API Platform is a REST and GraphQL framework to build modern API-driven projects.

We should rewrite the W3C API based on this framework (which did not existed when we developed the initial version of the W3C API).

This will provide long requested features such as:

• Filtering (see #76, #41, #68 )
• Default order (see #71) and Sorting
• Improved performances (built-in HTTP Cache Invalidation System) (see #60)
• Additional output formats (JSON-LD) (See #38)
• GraphQL
• and many other API Platform features.