[sai-gen] Remove all name-based type guessing heuristics

[r12f]

After this change, we will have no more type guessing based on object name. Each value size will have a default type. If the default type doesn't match, we shall specify the preferred type in the code.

As all the previous changes, no updates on generated contents:

r12f@r12f-dl380:~/data/code/sonic/DASH/dash-pipeline
$ diff SAI/SAI/experimental/ ~/data/code/sonic/DASH-exp/dash-pipeline/SAI/SAI/experimental/
r12f@r12f-dl380:~/data/code/sonic/DASH/dash-pipeline
$ diff SAI/lib/ ~/data/code/sonic/DASH-exp/dash-pipeline/SAI/lib/