Configurable Log Levels

**Is your feature request related to a problem? Please describe.**
It would be nice to be able to set the log level for the cli. Currently the log is very verbose and can result in large log files. We use dependency-check as part of our build pipeline and in some repos we see log files larger than 100GiB. This is mainly because each file that is scanned is traced in the log.
We save the log files only in case of an error but even in that case multiple gigabytes is too large for a log file.

**Describe the solution you'd like**
It would be nice to be able to set the log level e.g. to error/warn to only get the respective messages that are of interest if a scan should fail.