apidoc: Enrich route information with tags

The possible tags are:

• hidden: hide the api endpoint from the listing of documentation
• upcoming: the api endpoint is displayed in orange. No link to follow

the detailed documentation (cf. style.css).

• deprecated: the api endpoint is displayed in red, no link to follow

the detailed documentation (cf. style.css).

When no tags is provided, the initial behavior is kept.
That is, the endpoint is listed in /api/ and user can follow the details
by following the link.

Related T631