Currently, when signing on macOS fails, jpackage would report it as follows:

"codesign" failed with following output:
jpackage-tests/MacSignTest/testAppContentWarning/output/AppContentWarningMacSignTest.app: replacing existing signature
jpackage-tests/MacSignTest/testAppContentWarning/output/AppContentWarningMacSignTest.app: bundle format unrecognized, invalid, or unsuitable
In subcomponent: jpackage-tests/MacSignTest/testAppContentWarning/output/AppContentWarningMacSignTest.app/Contents/foo.1
jdk.jpackage.internal.util.function.ExceptionBox: jdk.jpackage.internal.Codesign$CodesignException
        at jdk.jpackage/jdk.jpackage.internal.util.function.ExceptionBox.toUnchecked(ExceptionBox.java:51)
        <stack trace omitted>
Error: jdk.jpackage.internal.Codesign$CodesignException

It prints only the command name without the arguments. Though for other errors, jpackage will print the full command line and the command output.

Rework reporting of the signing errors so that they are reported like other errors.

Additionally, when reporting external command errors, make jpackage always print a command's output, regardless of whether it is running in verbose or quiet mode.

Currently, it prints command output only in quiet mode, assuming that in verbose mode, the output is printed immediately after the command execution.

However, jpackage runs some commands quietly in verbose mode; if one of them fails, the user doesn't see its output.