Contacts and Memory stores: new API endpoints

Contacts

New endpoints added:

EndpointTitle
POST /contactsCreate a contact
GET /contactsList contacts
GET /contacts/:contact_idGet a contact
PATCH /contacts/:contact_idUpdate a contact
DELETE /v2/contacts/:contact_idDelete a contact

Memory stores

New endpoints added:

EndpointTitle
POST /memory_storesCreate a memory store
GET /memory_storesList memory stores
PATCH /memory_storesUpdate a memory store
DELETE /memory_storesDelete a memory store
GET /memory_stores/:memory_store_idGet a memory store
POST /memory_stores/:memory_store_id/assistants/:assistant_id/attachAttach a memory store to an agent
POST /memory_stores/:memory_store_id/assistants/:assistant_id/detachDetach a memory store from an agent
GET /memory_stores/:memory_store_id/contacts/:contact_id/memory_dataGet data for a specific memory store and contact
POST /memory_stores/:memory_store_id/contacts/:contact_id/attachAttach a contact to a memory store
POST /memory_stores/:memory_store_id/contacts/:contact_id/detachDetach a contact from a memory store