Reduce text manipulation in macros
Having the "intrinsiccv_" prefix added in a macro makes it hard to understand what functions are called and to locate where they are defined.
This change is consistent with C++ Core Guideline ES.30 [1].
This change is an enabler for a later change to add error handling to the API.
[1] https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Res-macros