Refactor ContentWorkerInterface methods signatures

While working on OFBIZ-6919 which was built on R13.07 I stumbled upon an issue due to r1652852 where Adrian improved the cacheKey in FormFactory.getFormFromLocation() by adding a delegator reference (Tenants). Actually I'm not even sure it was done at r1652852 because Adrian did not maintain the FormFactory svn history.

Anyway, to make a long story short I had to introduce a DispatchContext parameter when calling FormFactory.readFormDocument() when the code from R13.07 only passed a null.

This had an impact in the hierarchy tree because FormFactory.readFormDocument() was called in DataResourceWorker class, where the new code was called from renderDataResourceAsText(). So I instead of only passing a Delegator I decided to pass only a LocalDispatcher parameter in renderDataResourceAsText(), since we can get the Delegator from the LocalDispatcher. Doing so it had an impact on the renderDataResourceAsText hierarchy tree ending in DataResourceWorkerInterface and all related.

I finally decided to apply the same "Change Method Signature" refactoring pattern to all cases related to ContentWorkerInterface. No need to pass a delegator when you have LocalDispatcher!

Here I attach a patch for review, I'll commit in few days