Collector fails to detect file extension of command correctly on Windows
When checking if the base call of the command has a file extension, Collector incorrectly runs the `extname` function on the entire command string (`cmd`) instead of the just the base call (`cmd0`). As a result, it sometimes thinks that the base call has a file extension when it does not.
Example:
```
gradlew :my.project.api:generateDocs
```
In this case, no file extension should be detected.
issue