feat: EXPOSED-225 Support transaction timeout in SpringTransactionManager

[FullOfOrange]

related issue #1671

Simply changed the Spring Transaction's timeout to apply. Change the implementation to use the timeout implemented in the previous PR.

The test code for SpringTransactionManager is not database-specific, so I think we need to implement a module like withDB in the exposed-test module to test the actual behaviour. So I'm going to change the existing SpringTransactionManagerTest to be more extensible, at which point I'll add a real DB test for queryTimeout.

I wonder if the tests included in this PR are sufficient for this feature to be deployed.

[FullOfOrange]

DefaultTimeout has a value of -1. If it is not this value, the user has set a new value, so I added this condition.

[bog-walk]

spring-transaction tests run on H2 only, so an H2 hack will be needed.

I'm not the biggest fan of this, but if it's just one test and it gives us peace of mind for this feature, an option is using a recursive query to simulate a long-running query:

tm.executeAssert(initializeConnection = true, timeout = 1) {
    try {
        TransactionManager.current().exec(
           """
               WITH RECURSIVE T(N) AS (
               SELECT 1
               UNION ALL
               SELECT N+1 FROM T WHERE N<10000000
               )
               SELECT * FROM T;
            """.trimIndent(),
            explicitStatementType = StatementType.SELECT
        )
        fail("Should have thrown a timeout exception")
    } catch (cause: ExposedSQLException) {
        assertTrue { cause.cause is SQLTimeoutException }
    }
}

I also tried this in the ExposedTransactionManagerTest.kt file using the annotation @Transactional(timeout = 1) and it worked.
Do you think this is solid enough or do you think we need to try something in the spring boot tests?

[FullOfOrange]

Since timeout has already been tested in Exposed statements and in Transactions, I thought it would be okay to check that the SpringTransactionManager using Transactions sets the value in Transactions correctly.

However, since I know the implementation of this code, I'm thinking this way, and obviously I need to test the actual DB, I think the timeout using recursion is meaningful enough, so I'll add the test code you suggested. Thank you.