Use JDTUtils.toUri() for decompiled class file URIs (#624)

Replace manual jdt:// URI construction in getFileURI(IClassFile) with
JDTUtils.toUri(classFile) to align with eclipse.jdt.ls PR #3666.

This ensures the debugger generates the same URI format as the language
server, fixing the issue where classes with source code are opened twice
(once as .java, once as .class) during debugging.

Fixes #623
Related: eclipse-jdtls/eclipse.jdt.ls#3729

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: wenytang-ms

com.microsoft.java.debug.plugin/src/main/java/com/microsoft/java/debug/plugin/internal/JdtSourceLookUpProvider.java

@@ -466,15 +466,7 @@ private String getContents(IClassFile cf) {
     }
 
     private static String getFileURI(IClassFile classFile) {
-        String packageName = classFile.getParent().getElementName();
-        String jarName = classFile.getParent().getParent().getElementName();
-        try {
-            return new URI(JDT_SCHEME, "contents", PATH_SEPARATOR + jarName + PATH_SEPARATOR + packageName
-                    + PATH_SEPARATOR + classFile.getElementName(), classFile.getHandleIdentifier(), null)
-                    .toASCIIString();
-        } catch (URISyntaxException e) {
-            return null;
-        }
+        return JDTUtils.toUri(classFile);
     }
 
     private static String getFileURI(IResource resource) {