lxd/db/generate/db/method/v2: Create methods for reference tables
lxd/db/generate/db/method/v2: Create methods for reference tables

Removes auto-querying of reference tables (Config, Devices).
Instead, adds a "references" key to any method command, which instructs the
generator to generate a method for that entity's reference tables.

Signed-off-by: Max Asnaashari <291db2cb5046c5ac435c5cc205a1b9bc80a27f4b@canonical.com>

hallyn/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,lxc/lxd,hallyn/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,lxc/lxd,hallyn/lxd,stgraber/lxd,hallyn/lxd