use protobufs to define ccv state (cosmos#332)

* refactor UnbondingOpsIndex operations

Define message UnbondingOpsIndex in ccv protos.
Use UnbondingOpsIndex instead of []uint64 where applicable.

* update UnbondingOpsIndex tests

* refactor MaturedUnboundingOps store operations

Define message MaturedUnboundingOps in ccv protos.
Refactor code to use new message where applicable.

* update e2e tests

* refactor protobuf usage for ccv state

* add slash requests message

* use protobuf for storing slashes on consumer

* use protobuf for storing slash acks on provider

Co-authored-by: Jehan <jehan.tremback@gmail.com>

proto/interchain_security/ccv/consumer/v1/consumer.proto

@@ -50,3 +50,8 @@ message SlashRequest {
     interchain_security.ccv.v1.SlashPacketData packet = 1;
     cosmos.staking.v1beta1.InfractionType infraction = 2;
 }
+
+// SlashRequests is a list of slash requests for CCV consumer module
+message SlashRequests {
+  repeated SlashRequest requests = 1;
+}

proto/interchain_security/ccv/provider/v1/provider.proto

@@ -64,3 +64,9 @@ message HandshakeMetadata {
   string provider_fee_pool_addr = 1;
   string version                = 2;
 }
+
+// SlashAcks contains addesses of consumer chain validators
+// successfully slashed on the provider chain
+message SlashAcks {
+  repeated string addresses = 1;
+}

proto/interchain_security/ccv/v1/ccv.proto

@@ -46,3 +46,13 @@ message SlashPacketData {
   // tell if the slashing is for a downtime or a double-signing infraction
   cosmos.staking.v1beta1.InfractionType infraction = 3;
 }
+
+// UnbondingOpsIndex defines a list of unbonding operation ids.
+message UnbondingOpsIndex {
+  repeated uint64 ids = 1;
+}
+
+// MaturedUnbondingOps defines a list of ids corresponding to ids of matured unbonding operations. 
+message MaturedUnbondingOps {
+  repeated uint64 ids = 1;
+}