Add support for QUERY HTTP Method

[fredmaggiowski]

Feature Description

An RFC from IETF has been around for sometime now proposing the QUERY method to help requests with complex queries overcome the HTTP headers limitations: https://www.ietf.org/archive/id/draft-ietf-httpbis-safe-method-w-body-02.html#name-introduction

Since we are experiencing issues with query parameters support for _q, such as (but not limited to):

• encoding/decoding hassles
• max header length limitations
• different interfaces for basic queries (different qs) vs acl based queries (acl_rows, etc)

It would be nice to have a new http method support that allows to provide the desired query via the request body.

Desired solution

The crud service should expose a new API with the QUERY HTTP method, such API would accept a body containing all the queries that are needed, specifically:

• _q
• acl_*

For better interface coherence, the API would reject invocations mixing headers and query string parameters

Additional context

Such a feature might help overcoming limitations such as rond-authz/rond#13