nitweb: introduce /api/catalog/packages route
nitweb: introduce /api/catalog/packages route

List all packages in current catalog

Signed-off-by: Alexandre Terrasa <b30f4169e054ee7b8c243480bcfcef62416f3b08@moz-code.org>

privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit,privat/nit