Activation trigger should be more selective

[rgrunber]

The Quarkus extension and language server are triggered for onLanguage:java. This seems excessive. I can have an invisible project with just folders and Java source files (no Maven, no Gradle), and it still starts.

At the very least we could bring it down to just :

"workspaceContains:pom.xml",
"workspaceContains:build.gradle",
"workspaceContains:settings.gradle"

As for a better approach, maybe vscode-java could define some command that reads the build files for presence of Quarkus metadata (eg. quarkus-bom, quarkus-maven-plugin, io.quarkus.extension, etc), and emit some command for which vscode-quarkus simply listens with https://code.visualstudio.com/api/references/activation-events#onCommand

[rgrunber]

I think the easiest approach would be to make the extension activation a kind of "silent" activation that only starts the necessary language servers if the Maven/Gradle build files indicate they support Quarkus. This seems the easiest option.

The problem with the "onCommand:extension.sayHello" activation event is that it needs to be triggered by some other extension and having vscode-java or vscode-microprofile be responsible for Quarkus logic seems wrong.