No version manager name reported in CLI output, consider adding it

### Is your feature request related to a problem? Please describe

Hi there, excuse the snarky issue title, but it would be nice if asdf introduced itself in directories where it can't find `.tool-versions` instead of printing a cryptic message (which appears partially broken) without attribution.

Otherwise this output message can be quite confusing:

```
$ npm outdated
No version is set for command npm
Consider adding one of the following versions in your config file at
nodejs 16.13.2
```

Clearly there's some missing text here, probably assuming a location to a `.tool-versions` could be interpolated at the end of the second to last line?

Formatting-wise, showing `nodejs 16.13.2` without any list formatting is an odd choice as well, since at different viewport width it appears to be the end of the sentence above.

### Describe the proposed solution

Change this message to this instead:

```
$ npm outdated
asdf found no installed version for command `npm`.
You can add a version in `.tool-versions`, the following version is available: nodejs 16.13.2
```

That's of course assuming there's no alternative configuration file, but that's nothing a good link to a documentation page on the website won't fix if needed.

### Describe similar `asdf` features and why they are not sufficient

Since asdf is intercepting this call to `npm` I don't think this relates to other asdf features.

### Describe other workarounds you've considered

The only workaround would be for someone to be aware of `which npm` or `which -a npm` which sadly may be a bit too much to ask in some cases.

In my case, I forgot I installed `asdf` while also using `volta` and a Homebrew-installed version of node. I know, I know, that's a bit silly but I don't think it's that rare considering [this StackOverflow thread](https://stackoverflow.com/questions/74935373/no-version-is-set-for-command-npm-tool-versions-file-missing)

The issue does not name a file or test; start by searching the repository for the exact “No version is set for command” message and identify the CLI entry point that formats it. Reproduce the output with `npm outdated`, then verify that the revised message identifies asdf, formats the available version clearly, and remains correct for commands other than npm.

Written by the indexing model from the issue text.