Deprecate and eventually drop the internal cache

[cristinecula]

The layers above the data-nav are in a better position to decide how to handle the data. Data-nav should be dumbed down and always render from the data that is given to it.

We should add a no-cache attribute that disables the internal cache and makes it behave as suggested.
We should also add a deprecation warning when the cache is used so we can identify views that need migration.

[cristinecula]

The no-cache attribute would work great for views that use data-service.