Introduce log4j 2 for Spring's test suite

This commit adds a test runtime dependency on log4j 2 for every project
and migrates all log4j.properties files to log4j2-test.xml files.

Issue: SPR-14431

spring-orm/src/test/resources/log4j2-test.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+	<Appenders>
+		<Console name="Console" target="SYSTEM_OUT">
+			<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
+		</Console>
+	</Appenders>
+	<Loggers>
+		<Logger name="org.springframework.orm" level="warn" />
+		<Root level="error">
+			<AppenderRef ref="Console" />
+		</Root>
+	</Loggers>
+</Configuration>