python3-pip should recommend python-wheel-common instead of python3-wheel

[Jan]

The apt packages for the python `wheel` package split up the python code and the shell command. The python code lives in apt package `python3-wheel` while the shell command `wheel` lives in `python-wheel-common`.

`python3-pip` on Ubuntu 18.04.4 recommends `python3-wheel` but not `python-wheel-common`, so by default the `wheel` shell command does not get installed. If the `wheel` shell command does not exit, pip gives "Failed building wheel for X" errors when installing a package from pypi that does not have a wheel available for download. Installing `python-wheel-common` fixes the errors.

My guess is that pip assumes that if it can import `wheel` then the `wheel` shell command is also available, which is not currently the case. Changing the recommends from `python3-wheel` to `python-wheel-common` should fix this. `python-wheel-common` itself depends on `python3-wheel`, so this change should not break anything.

Tested on Ubuntu 18.04.4 LTS. Tested within a python venv.