shell: Remove few obj from the standard functions

This PR drop few objects from the standard function as discussed at !6069 (merged)

• I think static is not needed. It was not part of the __all__ before !6069 (merged), it's a mistake on my side
• SoftAxis and SoftCounter should be imported instead

from bliss.controllers.motors.soft import SoftAxis
from bliss.common.counter import SoftCounter

It would be better to deprecate only instead, but i don't really see how we could do that.

This can be discussed before merging, there is no hurry.

FYI @cyril.guilloud