Fix double living table schema race in IT

[Caideyipi]

Description

This PR fixes IoTDBPipeDoubleLivingIT#testBasicDoubleLiving by ensuring the receiver has synchronized the sender-side table data and schema before receiver-side table insertion starts. Without this wait, the receiver may try to auto-create a missing column from an insert statement that does not carry the column category, causing Unknown column category for s5. Cannot auto create column..

It also fixes the receiver-side tree insertion block to use receiverEnv.getConnection() instead of reusing the sender connection.

Verification

• mvn spotless:apply -pl integration-test -P with-integration-tests
• Attempted single IT verification with IoTDBPipeDoubleLivingIT#testBasicDoubleLiving; the run failed in setUp before reaching the test body because the local cluster did not start after 30 retries.

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This PR has:

• been self-reviewed.
• modified existing integration tests.

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Key changed/added classes (or packages if there are too many classes) in this PR

• integration-test/src/test/java/org/apache/iotdb/pipe/it/dual/tablemodel/manual/enhanced/IoTDBPipeDoubleLivingIT.java