Add alias support for install and uninstall

[chloegoh]

As per pradyunsg's comment, I have added the i and u aliases based off of McSinyx's implementation at #8137.

In summary, this fixes issue #8130 and allows users to install packages with i and add, and uninstall packages with u and remove.

$ pip help
Usage:
  pip <command> [options]

Commands:
  install, add, i             Install packages.
  download                    Download packages.
  uninstall, remove, u        Uninstall packages.
...

$ pip i numpy      # or pip add numpy
Collecting numpy
  Using cached numpy-1.22.3-cp38-cp38-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (16.8 MB)
Installing collected packages: numpy
Successfully installed numpy-1.22.3

$ pip u numpy      # or pip remove numpy
Found existing installation: numpy 1.22.3
Uninstalling numpy-1.22.3:
  Would remove:
...

Credits to McSinyx for implementing the alias mechanism.

[uranusjr]

Please fix linter errors.

[chloegoh]

Hi, I noticed that when I run tests locally using nox, there are some OS error messages triggered in tests/unit/test_command_install.py. I initially thought that it was caused by my environment, but seems like the same issue occurs in the CI tests. Would appreciate any guidance on this!

[uranusjr]

Could be (not sure) affected by https://github.blog/2022-04-12-git-security-vulnerability-announced/