Make TOML configuration reader scan for extension files

[ctrueden]

From this Zulip chat: a scenery/sciview use case requires the following --add-opens flags:

            "--add-opens=java.base/java.lang=ALL-UNNAMED",
            "--add-opens=java.base/java.lang.invoke=ALL-UNNAMED",
            "--add-opens=java.base/java.net=ALL-UNNAMED",
            "--add-opens=java.base/java.nio=ALL-UNNAMED",
            "--add-opens=java.base/java.time=ALL-UNNAMED",
            "--add-opens=java.base/java.util=ALL-UNNAMED",
            "--add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED",
            "--add-opens=java.base/sun.nio.ch=ALL-UNNAMED",
            "--add-opens=java.base/sun.util.calendar=ALL-UNNAMED"

This is quite a few more packages than the ones configured in the current fiji.toml. And it highlights an important consideration: extensions to Fiji might need to augment the Jaunch configuration with additional flags.

A general way to address this, which would be compatible with the current ImageJ Updater, would be for Jaunch to look for additional files matching some convention, such as jaunch/fiji-x-*.toml, and load those as well. Then an update site could ship, say, jaunch/fiji-x-sciview.toml, with the additional --add-opens flags needed for that update site's functionality to behave properly with Java 17+.

[imagesc-bot]

This issue has been mentioned on Image.sc Forum. There might be relevant details there:

https://forum.image.sc/t/jaunch-a-new-java-launcher-test-fiji-with-java-21/92058/1

[imagesc-bot]

This issue has been mentioned on Image.sc Forum. There might be relevant details there:

https://forum.image.sc/t/jaunch-a-new-java-launcher-test-fiji-with-java-21/92058/55

[ctrueden]

With c5101c3, TOML files get sourced based on the primary TOML config file's includes line. To tackle this issue, we could simply allow wildcards in there, so that additional config files could be dropped in matching the pattern.

[ctrueden]

As of this writing (b6b7a16), the includes list is not glob-expanded. However, Jaunch is resilient (if noisy) in response to non-existent TOML files:

if (!tomlFile.exists) warn("Included config file does not exist: $tomlFile")

which means we could, without changing Jaunch's source code, let Fiji support a limited TOML extensibility mechanism by sourcing some theoretical maybe-existent config files. But wildcards would still be much better, so that people's TOML extensions don't stomp on each other a la ImageJ's HandleExtraFileTypes.java feature.