rpc: Add experimental config params to allow for subscription buffer size control (tm v0.34.x) (#7230)

A workaround for #6729. Add parameters to control buffer sizes for
event subscription RPC clients. On some networks, buffering causes
clients to be dropped and/or events to be lost.

For additional context, see the discussion on #7188.

- Add experimental_subscription_buffer_size config parameter
- Add experimental_websocket_write_buffer_size config parameter
- Add experimental_close_on_slow_client config parameter

Co-authored-by: M. J. Fromberger <fromberger@interchain.io>

state/indexer/block/kv/kv_test.go

@@ -6,11 +6,12 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	db "github.com/tendermint/tm-db"
+
 	abci "github.com/tendermint/tendermint/abci/types"
 	"github.com/tendermint/tendermint/libs/pubsub/query"
 	blockidxkv "github.com/tendermint/tendermint/state/indexer/block/kv"
 	"github.com/tendermint/tendermint/types"
-	db "github.com/tendermint/tm-db"
 )
 
 func TestBlockIndexer(t *testing.T) {

state/indexer/block/kv/util.go

@@ -6,6 +6,7 @@ import (
 	"strconv"
 
 	"github.com/google/orderedcode"
+
 	"github.com/tendermint/tendermint/libs/pubsub/query"
 	"github.com/tendermint/tendermint/types"
 )

state/indexer/sink/psql/psql.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/gogo/protobuf/proto"
+
 	abci "github.com/tendermint/tendermint/abci/types"
 	"github.com/tendermint/tendermint/libs/pubsub/query"
 	"github.com/tendermint/tendermint/types"

state/indexer/sink/psql/psql_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/ory/dockertest/docker"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
 	abci "github.com/tendermint/tendermint/abci/types"
 	"github.com/tendermint/tendermint/types"
 

state/mocks/evidence_pool.go

@@ -4,6 +4,7 @@ package mocks
 
 import (
 	mock "github.com/stretchr/testify/mock"
+
 	state "github.com/tendermint/tendermint/state"
 
 	types "github.com/tendermint/tendermint/types"

state/mocks/store.go

@@ -4,6 +4,7 @@ package mocks
 
 import (
 	mock "github.com/stretchr/testify/mock"
+
 	state "github.com/tendermint/tendermint/state"
 
 	tendermintstate "github.com/tendermint/tendermint/proto/tendermint/state"