change use of errors.Wrap to fmt.Errorf with %w verb

Closes #4603

Commands used (VIM):

```
:args `rg -l errors.Wrap`
:argdo normal @q | update
```

where q is a macros rewriting the `errors.Wrap` to `fmt.Errorf`.

rpc/core/events.go

@@ -4,8 +4,6 @@ import (
 	"context"
 	"fmt"
 
-	"github.com/pkg/errors"
-
 	tmpubsub "github.com/tendermint/tendermint/libs/pubsub"
 	tmquery "github.com/tendermint/tendermint/libs/pubsub/query"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
@@ -32,7 +30,7 @@ func Subscribe(ctx *rpctypes.Context, query string) (*ctypes.ResultSubscribe, er
 
 	q, err := tmquery.New(query)
 	if err != nil {
-		return nil, errors.Wrap(err, "failed to parse query")
+		return nil, fmt.Errorf("failed to parse query: %w", err)
 	}
 
 	subCtx, cancel := context.WithTimeout(ctx.Context(), SubscribeTimeout)
@@ -85,7 +83,7 @@ func Unsubscribe(ctx *rpctypes.Context, query string) (*ctypes.ResultUnsubscribe
 	logger.Info("Unsubscribe from query", "remote", addr, "query", query)
 	q, err := tmquery.New(query)
 	if err != nil {
-		return nil, errors.Wrap(err, "failed to parse query")
+		return nil, fmt.Errorf("failed to parse query: %w", err)
 	}
 	err = eventBus.Unsubscribe(context.Background(), addr, q)
 	if err != nil {

rpc/core/mempool.go

@@ -2,11 +2,10 @@ package core
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"time"
 
-	"github.com/pkg/errors"
-
 	abci "github.com/tendermint/tendermint/abci/types"
 	mempl "github.com/tendermint/tendermint/mempool"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
@@ -68,7 +67,7 @@ func BroadcastTxCommit(ctx *rpctypes.Context, tx types.Tx) (*ctypes.ResultBroadc
 	q := types.EventQueryTxFor(tx)
 	deliverTxSub, err := eventBus.Subscribe(subCtx, subscriber, q)
 	if err != nil {
-		err = errors.Wrap(err, "failed to subscribe to tx")
+		err = fmt.Errorf("failed to subscribe to tx: %w", err)
 		logger.Error("Error on broadcast_tx_commit", "err", err)
 		return nil, err
 	}

rpc/core/net.go

@@ -1,10 +1,9 @@
 package core
 
 import (
+	"errors"
 	"fmt"
 
-	"github.com/pkg/errors"
-
 	"github.com/tendermint/tendermint/p2p"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 	rpctypes "github.com/tendermint/tendermint/rpc/lib/types"

rpc/core/tx.go

@@ -1,11 +1,10 @@
 package core
 
 import (
+	"errors"
 	"fmt"
 	"sort"
 
-	"github.com/pkg/errors"
-
 	tmmath "github.com/tendermint/tendermint/libs/math"
 	tmquery "github.com/tendermint/tendermint/libs/pubsub/query"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"