When publishing a codeql query pack with the --allow-prerelease option, if the version already exists, it should be overwritten

# Description

I am working on a custom query pack which I am publishing under my own account. This query pack is for the Vert.X Java framework (for more details, you can check #12844 ) and we will contribute it back to CodeQL once we have a more decent amount of queries. For the moment this is a separate query pack.

While this under heavy development and has no official released version, I am using a semver version such as `1.0.0-alpha`, as advised by @aeisenberg , who also suggested using the `--allow-prerelease` option. I was under the impression that when I execute:

```
codeql pack publish --github-auth-stdin --allow-prerelease
```

this would also overwrite the existing package, but this does not appear to be the case.

In my opinion, this option should be further extended to overwrite packages.

Deleting the versions manually Is a cumbersome process, especially, if you have no other versions, because it means you have to remove the package and then recreate it. This means you also have to manually make it publicly accessible. Every time.

I also think that there needs to be a version format that is treated as a snapshot for which this will be done automatically. For example, in the Java world, in Maven / Gradle, there's the concept that versions ending in `-SNAPSHOT` are (clearly) snapshots. Could, perhaps, versions such as `1.0.0-snapshot` be automatically treated as snapshots that will always be overwritten by default, instead of even having to pass in a parameter like this?