enhancement, api: consider creating a unify fault type for database filter?

Title: consider create a unify fault type for database filter

Description: I'm trying to implement fault injection for mysql proxy, the fault message definition is totally migrated from RedisFault https://github.com/envoyproxy/envoy/blob/a240824c376693b16ca8be51e435b95c42f3449f/api/envoy/extensions/filters/network/redis_proxy/v3/redis_proxy.proto#L186-L207 In the mean while, I notice that in filters/common/fault/v3 https://github.com/envoyproxy/envoy/blob/a240824c376693b16ca8be51e435b95c42f3449f/api/envoy/extensions/filters/common/fault/v3/fault.proto#L53-L57, The common fault delay is very limit that it cannot let users inject fault base on command type, mongo filter uses this fault type, but redis uses its own fault type, I guess they will reimplement their own fault type once some contributors want to extend other filters. It's there any plans to give a unified fault api for those filters?