RFR: 8287: Fix the JMX protocol extenders

[Alex Macdonald]

On Fri, 1 Nov 2024 14:04:04 GMT, Alex Macdonald <aptmac at openjdk.org> wrote:

> This PR addresses [JMC-8287](https://bugs.openjdk.org/browse/JMC-8287), in which the JMX protocol extenders were not running due to rjmx.ext not being visible by rjmx.common.
> 
> This bug would have originated from the movement of rjmx code from application to core last year.
> 
> Making rjmx.ext specify Fragment-Host on rjmx.common fixes the visiblity issue, and the protocol extenders both run as expected. This also fixes use-cases where plugins were expecting to have their protocols used but were failing due to the protocols not being picked up properly:
> 
> org.openjdk.jmc.rjmx.common.ConnectionException caused by java.net.MalformedURLException: Unsupported protocol:

Forgot to bring in the latest changes that fixed the Mac spotbugs, this force rebase gets it ontop of master

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PR Comment: https://git.openjdk.org/jmc/pull/602#issuecomment-2451999246