find my intel i7 processor model code by serial number

You can also look it up on Everymac.com

See https://everymac.com/systems/apple/macbook_pro/index-macbookpro.html Scroll down the list to your model (there are 3 different 15" late-2016 models). The CPU is listed; you can also click on the names to see many more details for each model.

Open a Terminal window and type the following:

sysctl -n machdep.cpu.brand_string

Intel(R) Core(TM) i7-10700K CPU @ 3.80GHz

That is what is reported for my 2020 27-in Core i7 iMac.

There is no looking up a CPU model by serial number since implicitly, your Mac has one serial number and one physical CPU.