[MetaModel] Switch FnParam to new Typing System

[jokap11]

Fixes function signatures with pointers ...
Should support this with the new typing system:

functions {
        extern unsigned<8> etiss_vload_encoded_unitstride(char* pV, unsigned<16> pVTYPE, unsigned<8> pVm, unsigned<16> pEEW, unsigned<8> pVd, unsigned<16> pVSTART, unsigned<16> pVLEN, unsigned<16> pVL, unsigned<64> pMSTART) [[etiss_needs_arch]];
        ...
    }

[PhilippvK]

Storing the actual type info in the FnParam class instead of just the size & kind is definitely the way to go. This was one of the main motivations to du the refactoring in the first place :D

thank you for the patch @jokap11, I will test it tomorrow.