FileUtils: add findResources methods
FileUtils: add findResources methods

They will be useful for finding scripts inside JARs on the classpath.

These methods were migrated from imagej-ui-swing; see:
https://github.com/imagej/imagej-ui-swing/blob/imagej-ui-swing-0.18.0/src/main/java/net/imagej/ui/swing/script/FileFunctions.java

scijava/scijava-common