Merge branch 'py3-cleanup-physical-mibs' into 'master'

py3. Cleanup OID iface MAC to IF-MIB::ifPhysAddress name.

See merge request !3410

(cherry picked from commit 72379057)

ac5d9367 py3. Cleanup OID iface MAC to IF-MIB::ifPhysAddress name.
a27e461d Fix flake.
94792d9d Fix black.
33046245 py3. Fix IfName to ifDescr.
dd48f0ff Fix mib name.