#60819 Azure Flexible Postgres sends a connection error LostConnectionDetector does not detect.

We see in Azure Flexible Postgres a combination of words the LostConnectionDetector does not detect. I have added to that class, and started a test class where new messages can be easily validated.

Exception message not matched:

SQLSTATE[08006] [7] connection to server at "xxx.writer.postgres.database.azure.com" (10.0.1.7), port 5432 failed: Connection refused
	Is the server running on that host and accepting TCP/IP connections? (Connection: pgsql, Host: xxx.writer.postgres.database.azure.com, Port: 5432, Database: forge, SQL: select * from "cache" where "key" in (illuminate:foundation:down))

(This may not be unique to Azure, it's just where we see this message)