feat: Add connection-level query timeout support

[rovshan-b]

Query Timeout Support via x-query-timeout-ms gRPC Header

This change adds support for propagating query timeouts to the IOMETE Flight SQL server using a custom x-query-timeout-ms gRPC header. When a timeout is configured, the header is attached to every query execution request, allowing the server to enforce it server-side.

Statement-level timeout

Use the standard JDBC API on any Statement or PreparedStatement:

Statement stmt = connection.createStatement();
stmt.setQueryTimeout(30); // seconds
stmt.executeQuery("SELECT ...");

The header x-query-timeout-ms: 30000 will be sent with the request. A value of 0 means no timeout (default).

Connection-level (global) timeout

Set a default timeout for all queries on a connection via the JDBC URL or Properties:

jdbc:arrow-flight-sql://host:port?queryTimeout=60

Properties props = new Properties();
props.setProperty("queryTimeout", "60"); // seconds
Connection conn = DriverManager.getConnection(url, props);

All statements on this connection will include x-query-timeout-ms: 60000 unless overridden at the statement level.

Precedence

Statement-level timeout takes priority over the connection-level default. If setQueryTimeout(0) is called on a statement, it falls back to the connection-level value. If neither is set, no header is sent.

Configuration	Header sent
stmt.setQueryTimeout(30)	x-query-timeout-ms: 30000
?queryTimeout=60 (no statement timeout)	x-query-timeout-ms: 60000
stmt.setQueryTimeout(30) + ?queryTimeout=60	x-query-timeout-ms: 30000
Neither configured	(no header)