ISPN-4559 Replace fails with cache loader

https://issues.jboss.org/browse/ISPN-4559
https://issues.jboss.org/browse/ISPN-4649
Looks better now, thanks :)

But I don't think it would be that complex, I was just thinking of just moving the `CacheLoaderInterceptor.skipLoadForWriteCommand()` method in the commands themselves. It's true that the names I proposed are a bit misleading, maybe I should have said `canSkipCacheLoader()` and `canSkipRemoteGet()` instead...

In the end, I think the `IGNORE_RETURN_VALUES` flag should be enough for regular use, and a better solution would be to remove the special handling for `SKIP_CACHE_LOAD` altogether. WDYT, maybe for 8.0?