Make the list proxyInformation and the set resolving of a LazyLinkingResource be created lazily

[rubenporras]

By doing that, when resources already linked are loaded from storage, no memory needs to be allocated for the proxyInformation list and the resolving set.

[szarnekow]

new ArrayList doesn't allocate the internal array. What kind of savings did you observe from the suggested change?

[rubenporras]

Hi Sebastian,

that is true, the internal array is not allocated. However, the ArrayList object itself has to be allocated. It is not to be a massive win, but it the object allocation can be saved, it will be slightly better. Our application is a multi-threaded application that deals with many resources loaded on demand and short-lived. Since the code of PR #3318 which is not complex, I think it is worth the effort.

Also note, that even though new ArrayList is not allocating a new array, the current implementation of LazyLinkingResource.clearLazyProxyInformation() is allocating a list with an new allocated internal array if the proxyInformation had entries before. This last point can be fixed by just calling clear on the existing list, which is also part of the proposed PR.