Rework Callback::BindImpl() to fix #859
This MR:
- reworks Callback::BindImpl() to fix #859 (closed)
- forwards arguments in more places to decrease copy operation
- fix a wifi issue in WifiPhyOperatingChannel::GetPrimaryChannelNumber() spotted by sanitizers
There are still a couple of issues spotted by running ./test.py with sanitizers enabled. Indeed, the following tests are failing:
- tcp-header
- wifi-ac-mapping