Improve RedisCacheManagerBuilder to expose applied RedisCacheConfiguration

[quaff]

Before this commit, we need reflection if we want customization base on applied RedisCacheConfiguration, it's not conventional.

Take spring-boot RedisCacheManagerBuilderCustomizer for example:

	@Bean
	@ConditionalOnClass(name = "org.springframework.data.redis.cache.RedisCacheConfiguration")
	RedisCacheManagerBuilderCustomizer redisCacheManagerBuilderCustomizer() {
		return builder -> {
			RedisCacheConfiguration oldDefaultCacheConfiguration = ReflectionUtils.getFieldValue(builder,
					"defaultCacheConfiguration");
			RedisCacheConfiguration newDefaultCacheConfiguration = oldDefaultCacheConfiguration
				.serializeValuesWith(SerializationPair.fromSerializer(new CompactJdkSerializationRedisSerializer()));
			builder.cacheDefaults(newDefaultCacheConfiguration);
		};
	}

after this commit, it could be:

	@Bean
	@ConditionalOnClass(name = "org.springframework.data.redis.cache.RedisCacheConfiguration")
	RedisCacheManagerBuilderCustomizer redisCacheManagerBuilderCustomizer() {
		return builder -> {
			builder.cacheDefaults(builder.cacheDefaults()
				.serializeValuesWith(SerializationPair.fromSerializer(new CompactJdkSerializationRedisSerializer())));
		};
	}

[jxblum]

Thank you for the contribution. This has been reviewed, polished and merged in main (for 3.2.x), 3.1.x and 3.0.x.

However, I am not certain that I will back port this change to SD Redis 2.7.x.