ERv2: Support for KMS

[lechuk47]

Support KMS in Erv2

[esron]

LGTM

[hemslo]

Should we make default explicit instead of a hard coded string? For example, ObjectFactory register all factories in __init__

class ObjectFactory(Generic[T]):
    def __init__(self, factories, default_factory = None) -> None:
        self._factories = factories
        self._default_factory = default_factory

    def get_factory(self, id: str) -> T:
        if id not in self._factories and self._default_factory:
            return self._default_factory
        return self._factories[id]

init once and immutable

[lechuk47]

I like it. Added.