[Junie]: display scala 3 extension in editor breadcrumbs

[jetbrains-junie]

📌 PR Details

• 🔗 Issue: #SCL-23500
• 🏷 Title: display scala 3 extension in editor breadcrumbs

📝 Original Issue Description

Enable breadcrumbs if not yet
https://www.jetbrains.com/help/idea/settings-editor-breadcrumbs.html

object Utils {
  object Inner {
    extension (i: Int) {
      def myExtension1: String = {
        //PLACE CARET HERE
      }
    }
  }
}

Note that "extension" is lost in the breadcrumbs:

It feels like the method myExtension1 is defined in object Inner directly.
It can confuse in big code bases.
I was confused in the sources of sbt 2.0.0-M3 in sbt.ProjectExtra#extract method which is actually an extension method on Project.type, which is not visible in the breadcrumbs.

We might display extension(TypeName) (without all the details, like type parameters, etc...

📊 Junie Summary

A breadcrumb UI enhancement was implemented for Scala 3 extension methods in the IntelliJ IDEA IDE, enabling the display of "extension(TypeName) methodName" in breadcrumbs. The implementation is error-free, and all relevant tests were confirmed to pass successfully.