[Console] Fix issue with reserved keyword "command" as argument name

[flkasper]

Q	A
Branch?	7.1
Bug fix?	no
New feature?	yes
Deprecations?	no
Issues	Fix #54729
License	MIT

In the InputArgument constructor, an InvalidArgumentException is thrown if the reserved keyword command is used as the name and is not the argument command name.

The change to this PR is a new non-breaking feature, but could also be merged into older versions as a bugfix.

[chalasr]

Thanks for the PR. Although it is hack-ish, I'm ok with the argument description' string-based check.
To prevent regressions we need a test case that makes us able to catch a potential change to the command argument description and forces us to sync the description used in InputArgument.

Changing the milestone for 7.2 also as 7.1 is in feature-freeze and this is a DX improvement, not a bugfix.

[fabpot]

An alternative could be to rename the internal command name to __command to avoid the potential clash.

[flkasper]

An alternative could be to rename the internal command name to __command to avoid the potential clash.

See discussion at #54729.
A collision would not be 100% avoidable with a renaming.

It would also be a major breaking change.
Many libraries that are based on Symfony would also have to be adapted; in Symfony's own code alone, this is used in many places to execute other commands.