Parse 'pipx run' input and infer the app name like 'pipx install'

How would this feature be useful?

This would make pipx run immensely more user friendly and easier to type without resorting to a readme or scanning the --help for the correct run syntax.

Background

Given an app called tap-mysql currently, pipx run tap-mysql --help works great! It knows that the plugin's name is tap-mysql and it attempts to run a command with that same name (tap-mysql --help in this example),

Given an a more complex pip_url (like tap-mysql==1.4 or git+https://github.com/singer-io/tap-mysql.git), could pipx doesn't use the detected package name to attempt the same. Instead, the package is installed and then the command will immediately fail.

$ pipx run tap-mysql --help
usage: tap-mysql [-h] -c CONFIG...
... # works perfectly
$ pipx run tap-mysql==1.17.5 --help
'tap-mysql==1.17.5' executable script not found in package 'tap-mysql==1.17.5'. Available executable scripts: tap-mysql

So in theory, we could put those two things together and let this work out of box?: pipx run <any_pip_url> --help

Describe the solution you'd like

The requested feature improvement would be to use the detected package name as the app name if --spec is not detected and if the argument passed to pipx run was a complex pip_url, such as a git ref or a version-pinned ref.

Already pipx does have the logic to detect package name, and pipx run already accepts simple package names without having to separately pass the app name.

pipx run tap-mysql --help                                              # already works today
pipx run tap-mysql==1.17.5 --help                                      # would be new
pipx run git+https://github.com/singer-io/tap-mysql@main.git --help    # would be new

Describe alternatives you've considered

The workaround is to explicitly send the executable name and pip URL separately using pipx run --spec <pip_url> <app_name>. However, this is not very portable and since most pipx commands do not require remembering the --spec.

Instead of running like this:

pipx run git+https://github.com/singer-io/tap-mysql.git --help

or

pipx run tap-mysql==1.0.5 --help

We would need to add tap-mysql at the end also.

pipx run --spec=git+https://github.com/singer-io/tap-mysql.git tap-mysql --help