Fix queueStore stops working with concurrent PUT/DELETE requests (#8381)

- This PR fixes situation to avoid underflow, this is possible
  because of disconnected operations in replay/sendEvents
- Hold right locks if Del() operation is performed in Get()
- Remove panic in the code and use loggerOnce
- Remove Timer and instead use Ticker instead for proper ticks

pkg/event/target/mysql.go

@@ -54,6 +54,7 @@
 package target
 
 import (
+	"context"
 	"database/sql"
 	"encoding/json"
 	"errors"
@@ -311,7 +312,7 @@ func (target *MySQLTarget) executeStmts() error {
 }
 
 // NewMySQLTarget - creates new MySQL target.
-func NewMySQLTarget(id string, args MySQLArgs, doneCh <-chan struct{}) (*MySQLTarget, error) {
+func NewMySQLTarget(id string, args MySQLArgs, doneCh <-chan struct{}, loggerOnce func(ctx context.Context, err error, id interface{})) (*MySQLTarget, error) {
 	var firstPing bool
 	if args.DSN == "" {
 		config := mysql.Config{
@@ -363,9 +364,9 @@ func NewMySQLTarget(id string, args MySQLArgs, doneCh <-chan struct{}) (*MySQLTa
 
 	if target.store != nil {
 		// Replays the events from the store.
-		eventKeyCh := replayEvents(target.store, doneCh)
+		eventKeyCh := replayEvents(target.store, doneCh, loggerOnce, target.ID())
 		// Start replaying events from the store.
-		go sendEvents(target, eventKeyCh, doneCh)
+		go sendEvents(target, eventKeyCh, doneCh, loggerOnce)
 	}
 
 	return target, nil