[fix] Add explicit wheel dependency for virtualenv

[gamesh411]

Python package wheel provides the bdist_wheel command required for
building wheels for codechecker-api and codechecker-api-shared
packages. This modification ensures the wheel dependency for each
virtualenv.

[gamesh411]

I had a problem on Ubuntu 20.04 (inside WSL2) with making a new virtualenv (make venv). bdist_wheel was needed but not found when building codechecker-api and its -shared package's wheels.

[gamesh411]

I could have injected the dependency into the requirements.txt files and/or could have specified an exact version number for wheel, but my reasoning behind not doing so is this:
The wheel package is only used for building the other two packages, and thus will not contribute to the runtime code directly, so there are no API contracts to uphold/break. So at build time, an up-to-date version of the package seems like a good idea to me.

[whisperity]

On a real Ubuntu 18.04 I was able to do pip install codechecker-api codechecker-api-shared, however, pip install codechecker failed:

Building wheels for collected packages: codechecker
  Running setup.py bdist_wheel for codechecker ... error
  Complete output from command /home/w/TEMPORARY_CRAP_ENV/bin/python3 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-x9i4yi32/codechecker/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" bdist_wheel -d /tmp/tmpg1_qjztfpip-wheel- --python-tag cp36:
  /usr/lib/python3.6/distutils/dist.py:261: UserWarning: Unknown distribution option: 'long_description_content_type'
    warnings.warn(msg)
  usage: -c [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
     or: -c --help [cmd1 cmd2 ...]
     or: -c --help-commands
     or: -c cmd --help

  error: invalid command 'bdist_wheel'

  ----------------------------------------
  Failed building wheel for codechecker
  Running setup.py clean for codechecker
Failed to build codechecker

[tomrittervg]

I hit errors with bdist_wheel not being found and this patch resolved them for me.

[whisperity]

Right now, pip install codechecker seems to work on all major systems. @gamesh411 Can you check in let's say a Docker env whether most of the LTS Linuxes (Ubuntu 20, 22, and maybe latest Debian, and Alpine Linux as well?) and their default Python versions can do the pip install. If so, this change is actually not needed? If not, then we should move forward with reviewing this patch.

[whisperity]

Why is this better than having the package specified in the requirements.txt?

[bruntib]

I believe, @gamesh411 had this answer for this question from earlier:

The wheel package is only used for building the other two packages, and thus will not contribute to the runtime code directly, so there are no API contracts to uphold/break. So at build time, an up-to-date version of the package seems like a good idea to me.

However, I would also agree to put dependencies in the requirements.txt of the venv_dev target. This target is dedicated for dependencies during development and not during usage.

[whisperity]

@bruntib @gamesh411 By "other two packages" we mean the API, right? If yes, then I do not see why we need these in the "main" CodeChecker package or venv, as these installs could be scoped into the API Makefile: https://github.com/Ericsson/codechecker/blob/v6.23.1/web/api/Makefile#L60