Ergonomics detect missing support for apisupport projects

[jtulach]

• this is the continuation of Update JavaIndex when a file without its project is opened #9622
• the steps to reproduce are a variant of previous steps

Steps to Reproduce

Let's reproduce with ergonomics.

• let's build it all as $ JAVA_HOME=/jdk-21 ant build
• let's clean previous debris: rm -rf nbbuild/testuserdir/
• let's run it: netbeans$ JAVA_HOME=/jdk-21 ant tryme
• let's open internal terminal and netbeans ide/projectui/src/org/netbeans/modules/project/ui/ProjectsRootNode.java
  • that enables Java Support, but not API support
• there should be errors when importing types for any other project
  • with 8a5d960 that gets detected
  • and the user is asked to open the project to fix the problem

• When the project is opened and the classpath scanning finishes, then the errors disappear.

Task list

• Write some tests, maybe?