Add default implements for IAsyncObserver and IAsyncBatchObserver #2147

Job	Run time
Build (ubuntu-latest)	2m 9s
Consul provider tests (Consul)	5m 41s
Azure Storage provider tests	0s
Build (windows-latest)	4m 14s
Azure Cosmos DB provider tests	0s
AWS DynamoDB provider tests (DynamoDB)	5m 43s
MariaDB/MySQL provider tests (MySql)	2m 52s
PostgreSQL provider tests (PostgreSql)	3m 23s
Microsoft SQL Server provider tests (SqlServer)	3m 3s
Redis provider tests (Redis)	5m 52s
ZooKeeper provider tests (ZooKeeper)	2m 57s
	35m 54s

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