Impact of missing validate_call

[fopina]

validate_call was removed in 97ea607 to improve import time

What is the impact of that, of leaving all validation up to the server?

Can it be re-added in some lazy way, so we can have call validation while keeping this lower import time?

#21 has import time comparisons

[fopina]

#45 also removing "required" properties validation in case it needs to be revisited