LazyTrait and apply_transform API issue

[wyli]

Describe the bug
The pattern of invoking transforms with a lazy parameter depending on isinstance(transform, LazyTrait) is problematic

MONAI/monai/transforms/transform.py

Line 98 in e6ec945

return transform(data, lazy=lazy) if isinstance(transform, LazyTrait) else transform(data)

because the LazyTrait API doesn't provide a __call__ design.

MONAI/monai/transforms/traits.py

Lines 22 to 24 in e6ec945

	class LazyTrait:
	"""
	An interface to indicate that the transform has the capability to execute using

(introduced since #6537)

[atbenmurray]

@wyli please include me in this discussion.
@mjorgecardoso

[atbenmurray]

I'm hoping that we can continue with the implementation of lazy resampling for 1.4. We should have a discussion about the use of interfaces and the design choices around them as part of this.