RFR: 8311653: Modify -XshowSettings launcher behavior

[Sean Coffey]

On Mon, 24 Jul 2023 16:00:52 GMT, Sean Coffey <coffeys at openjdk.org> wrote:

> Modify the -XshowSettings launcher option to print non-verbose settings details of all components by default. Verbose settings details will be printed via the -XshowSettings:all option. Modify the -XshowSettings option to reject bad values passed to it. Print an error message in such scenarios and abort the VM launch.

Thanks for the feedback to date. I think I've captured all of it in recent update.

main changes: 
I've tightened up validation of input values to -XshowSettings and improved testing in this area. 
Updated java -X output to highlight difference between -XshowSettings and -XshowSettings:all

-------------

PR Comment: https://git.openjdk.org/jdk/pull/15001#issuecomment-1650433071