feat(auth): Implement Tenant token

Make meilisearch support JWT authentication signed with meilisearch API keys
using HS256, HS384 or HS512 algorithms.

Related spec: https://github.com/meilisearch/specifications/pull/89
Fix #1991

meilisearch-http/tests/auth/mod.rs

@@ -1,6 +1,7 @@
 mod api_keys;
 mod authorization;
 mod payload;
+mod tenant_token;
 
 use crate::common::Server;
 use actix_web::http::StatusCode;