Return correct match and handle Uberjars

https://repo1.maven.org/maven2/com/github/tomakehurst/wiremock-standalone/2.24.1/wiremock-standalone-2.24.1.jar is a massive uberjar with over 30+ bundled packages.

https://repo1.maven.org/maven2/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.pom is matched to it even though https://repo1.maven.org/maven2/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.pom and https://repo1.maven.org/maven2/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.jar would be better matches.

We should ensure that:
1. we return the correct match in this case
2. we always index POMs as files