Add TxsByEvent gRPC endpoint (#7842)

* add service definition for TxsByEvents

* add TxsByEvent gRPC endpoint

* fix lint

* fix test

* review changes

* review changes

* fix proto descriptions

* review changes

* fix lint

* review changes

* Update proto/cosmos/tx/v1beta1/service.proto

* review changes

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

types/query/filtered_pagination.go

@@ -35,7 +35,7 @@ func FilteredPaginate(
 	}
 
 	if limit == 0 {
-		limit = defaultLimit
+		limit = DefaultLimit
 
 		// count total results when the limit is zero/not supplied
 		countTotal = true

types/query/pagination.go

@@ -6,9 +6,9 @@ import (
 	"github.com/cosmos/cosmos-sdk/store/types"
 )
 
-// defaultLimit is the default `limit` for queries
-// if the `limit` is not supplied, paginate will use `defaultLimit`
-const defaultLimit = 100
+// DefaultLimit is the default `limit` for queries
+// if the `limit` is not supplied, paginate will use `DefaultLimit`
+const DefaultLimit = 100
 
 // Paginate does pagination of all the results in the PrefixStore based on the
 // provided PageRequest. onResult should be used to do actual unmarshaling.
@@ -33,7 +33,7 @@ func Paginate(
 	}
 
 	if limit == 0 {
-		limit = defaultLimit
+		limit = DefaultLimit
 
 		// count total results when the limit is zero/not supplied
 		countTotal = true