Improve logging in TransactionalTEL

This commit makes the logging in TransactionalTestExecutionListener
consistent for both starting and ending transactions. Specifically,
the current TestContext is now included in the informational log
statement when starting a new transaction.

Issue: SPR-11323

Author: sbrannen

spring-test/src/main/java/org/springframework/test/context/transaction/TransactionalTestExecutionListener.java

@@ -273,8 +273,9 @@ private void startNewTransaction(TestContext testContext, TransactionContext txC
 		txContext.startTransaction();
 		++this.transactionsStarted;
 		if (logger.isInfoEnabled()) {
-			logger.info("Began transaction (" + this.transactionsStarted + "): transaction manager ["
-					+ txContext.transactionManager + "]; rollback [" + isRollback(testContext) + "]");
+			logger.info(String.format(
+				"Began transaction (%s) for test context %s; transaction manager [%s]; rollback [%s]",
+				this.transactionsStarted, testContext, txContext.transactionManager, isRollback(testContext)));
 		}
 	}
 
@@ -288,8 +289,9 @@ private void startNewTransaction(TestContext testContext, TransactionContext txC
 	private void endTransaction(TestContext testContext, TransactionContext txContext) throws Exception {
 		boolean rollback = isRollback(testContext);
 		if (logger.isTraceEnabled()) {
-			logger.trace("Ending transaction for test context " + testContext + "; transaction manager ["
-					+ txContext.transactionStatus + "]; rollback [" + rollback + "]");
+			logger.trace(String.format(
+				"Ending transaction for test context %s; transaction status [%s]; rollback [%s]", testContext,
+				txContext.transactionStatus, rollback));
 		}
 		txContext.endTransaction(rollback);
 		if (logger.isInfoEnabled()) {