macOS: use thegetOpinionatedStringContents same as paste for dragging (#13212)

The only difference of getting the string contents between dragging
pasteboard and general pasteboard is the URL now. It was first
introduced in #4962, I don't why it was added, since `public.url` often
comes with `public.utf8-plain-text` when dragging.

I also check with iTerm's
[PTYTextView](f267f243e5/sources/TerminalView/PTYTextView.m (L307)),
it doesn't register URL either, so I think it's safe for us to remove
it.

> I checked the iTerm's source after my changes, I hope that doesn't
violates any licensing

macos/Sources/Ghostty/Surface View/SurfaceView_AppKit.swift

@@ -2220,7 +2220,6 @@ extension Ghostty.SurfaceView {
     static let dropTypes: Set<NSPasteboard.PasteboardType> = [
         .string,
         .fileURL,
-        .URL
     ]
 
     override func draggingEntered(_ sender: any NSDraggingInfo) -> NSDragOperation {
@@ -2240,24 +2239,7 @@ extension Ghostty.SurfaceView {
     override func performDragOperation(_ sender: any NSDraggingInfo) -> Bool {
         let pb = sender.draggingPasteboard
 
-        let content: String?
-        if let url = pb.string(forType: .URL) {
-            // URLs first, they get escaped as-is.
-            content = Ghostty.Shell.escape(url)
-        } else if let urls = pb.readObjects(forClasses: [NSURL.self]) as? [URL],
-           urls.count > 0 {
-            // File URLs next. They get escaped individually and then joined by a
-            // space if there are multiple.
-            content = urls
-                .map { Ghostty.Shell.escape($0.path) }
-                .joined(separator: " ")
-        } else if let str = pb.string(forType: .string) {
-            // Strings are not escaped because they may be copy/pasting a
-            // command they want to execute.
-            content = str
-        } else {
-            content = nil
-        }
+        let content = pb.getOpinionatedStringContents()
 
         if let content {
             DispatchQueue.main.async {