Add sandesh_send_rate_limit parameter

Related-Bug: PROD-29404 (PROD:29404)

Generators of big environments with high traffic and modification requests
can generate huge amount of sandesh messages. It can cause oveloading
and high resource consumption of analytics services.
Amount of sandesh messages can be decreased using
`sandesh_send_rate_limit`.

Change-Id: Idf6055c57e5ca5d2b608ee59ad2c104daadc5c0a
(cherry picked from commit 4c4d45a70c029ac3ed0ee7c254eb6ebc983c6d6a)
18 files changed