Allow to overwrite input-parameters in nested manifests

[lukaszo]

Description

Currently if one manifest is running another one. Using capact-action we have no way to set input-parameters for nested parameters. Using Action Policy we can overwrite or pass new additional input but not input parameters.

For example in the RocketChat example we are installing MongoDB. We cannot set there for example number of replicas. For now we need to separately install Mongo DB and later pass a TypeInstance with MongoDB to the RocketChat.

We could extend our Policy and not only inject additionalInput but also we could do it with input itself.

Reason

This would allow to use "MegaManifests" with pre-configured variables. It would also make Capact more flexible when using nested Manifests.

[lukaszo]

For a MongoDB we will move replicas and other fields to an additional input.