Improve reporting of missing/incorrect authorization in remote operations

[jesse-gallagher]

Currently, when using a non-anonymous-allowing remote server without specifying credentials, the Maven mojos fail with generic I/O exceptions. It would be better to catch the specific response code and display an appropriate error message to the user.

[jesse-gallagher]

There's similar trouble when the tooling isn't installed at all. It presumably received 404s, but outputs generic errors:

Feb 12, 2021 5:06:02 PM org.apache.http.impl.execchain.RetryExec execute
INFO: I/O exception (java.net.SocketException) caught when processing request to {}->http://surinam.galaxia:9001: Broken pipe (Write failed)
Feb 12, 2021 5:06:02 PM org.apache.http.impl.execchain.RetryExec execute
INFO: Retrying request to {}->http://surinam.galaxia:9001
Feb 12, 2021 5:06:02 PM org.apache.http.impl.execchain.RetryExec execute
INFO: I/O exception (java.net.SocketException) caught when processing request to {}->http://surinam.galaxia:9001: Broken pipe (Write failed)
Feb 12, 2021 5:06:02 PM org.apache.http.impl.execchain.RetryExec execute
INFO: Retrying request to {}->http://surinam.galaxia:9001
Feb 12, 2021 5:06:02 PM org.apache.http.impl.execchain.RetryExec execute
INFO: I/O exception (java.net.SocketException) caught when processing request to {}->http://surinam.galaxia:9001: Protocol wrong type for socket (Write failed)
Feb 12, 2021 5:06:02 PM org.apache.http.impl.execchain.RetryExec execute
INFO: Retrying request to {}->http://surinam.galaxia:9001