[MDEP-723] Allow copying dependencies via CLI coordinates instead of pom file

**[Adrian Cole](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=adriancole)** opened **[MDEP-723](https://issues.apache.org/jira/browse/MDEP-723?redirect=false)** and commented

It would be nice to get transitive deps into a libs dir without having to define a pom.xml first. Here's what I'm doing now.

```sh
1. Dist includes large dependencies needed by streams and connect: retain only broker and ZK.
1. We can do this because broker is independent from both kafka-streams and connect modules.
1. See https://issues.apache.org/jira/browse/KAFKA-10380
cat > pom.xml <<-EOF

4.0.0

io.zipkin.kafka
get-kafka
0.1.0-SNAPSHOT
pom

org.apache.kafka
kafka_${SCALA_VERSION}
${KAFKA_VERSION}


org.slf4j
slf4j-log4j12
1.7.30

EOF
mvn -q --batch-mode dependency:copy-dependencies -DoutputDirectory=libs && rm pom.xml
```

---
No further details from [MDEP-723](https://issues.apache.org/jira/browse/MDEP-723?redirect=false)

The issue does not name any repository files, tests, or entry points. Start by locating the dependency:copy-dependencies CLI implementation and its existing command-line tests, then determine how coordinates and transitive dependencies should be represented. Done means the CLI can copy the requested coordinates and their transitive dependencies into the specified directory without requiring a pom.xml.

Written by the indexing model from the issue text.