This commit fixes problems with file path separators and command
line argument quoting in Maven plug integration tests when run on
Windows.
Fixes gh-20244
This commit upgrades the default CNB builder image from
cloudfoundry/cnb:0.0.43-bionic to cloudfoundry/cnb:0.0.53-bionic.
It also adds integration tests for the Maven and Gradle plugins
to verify both versions are supported.
This commit changes uses of ClassLoader.loadClass to Class.forName for
consistency with what was initiated in #19342 and better compatibility
with GraalVM.
Closes gh-19824
