Expose API / command to get all quarkus properties as k/v pairs

[fbricon]

In a JBang file with quarkus dependencies, we can use the //Q:CONFIG directive to configure the application

From jbang-vscode, I'd like to be able to fetch the list of available key/value pairs by calling a vscode-quarkus command (as a follow up of jbangdev/jbang-vscode#102).

The "project" not being a Maven/Gradle project might be an issue. Hopefully not. We just need to find the properties from the underlying project's classpath.

I imagine the command would just need the file URI as a parameter. From there it should be able to find the Java project it belongs to, then collect all dependencies from the classpath. Getting deployment jars when it's neither a maven or gradle project might be tricky.

Anyways, nothing urgent, really a nice to have.

[angelozerr]

I think we will need this feature to support in Qute template {config:|}