Make focusedEditorContent a function marked as expensive

Core/Sources/PromptToCodeService/OpenAIPromptToCodeService.swift

@@ -31,7 +31,7 @@ public final class OpenAIPromptToCodeService: PromptToCodeServiceType {
             return userPreferredLanguage.isEmpty ? "" : " in \(userPreferredLanguage)"
         }()
 
-        let editor: EditorInformation = XcodeInspector.shared.focusedEditorContent ?? .init(
+        let editor: EditorInformation = XcodeInspector.shared.getFocusedEditorContent() ?? .init(
             editorContent: .init(
                 content: source.content,
                 lines: source.lines,

Tool/Sources/ChatContextCollectors/ActiveDocumentChatContextCollector/GetEditorInfo.swift

@@ -3,6 +3,6 @@ import SuggestionModel
 import XcodeInspector
 
 func getEditorInformation() -> EditorInformation? {
-    return XcodeInspector.shared.focusedEditorContent
+    return XcodeInspector.shared.getFocusedEditorContent()
 }
 

Tool/Sources/XcodeInspector/SourceEditor.swift

@@ -30,7 +30,8 @@ public class SourceEditor {
 
     /// Get the content of the source editor.
     ///
-    /// - note: This method is expensive.
+    /// - note: This method is expensive. It needs to convert index based ranges to line based
+    /// ranges.
     public func getContent() -> Content {
         let content = element.value
         let selectionRange = element.selectedTextRange

Tool/Sources/XcodeInspector/XcodeInspector.swift

@@ -35,8 +35,11 @@ public final class XcodeInspector: ObservableObject {
     @Published public fileprivate(set) var focusedElement: AXUIElement?
     @Published public fileprivate(set) var completionPanel: AXUIElement?
 
-    #warning("TODO: make it a function and mark it as expensive")
-    public var focusedEditorContent: EditorInformation? {
+    /// Get the content of the source editor.
+    ///
+    /// - note: This method is expensive. It needs to convert index based ranges to line based
+    /// ranges.
+    public func getFocusedEditorContent() -> EditorInformation? {
         guard let documentURL = XcodeInspector.shared.realtimeActiveDocumentURL,
               let workspaceURL = XcodeInspector.shared.realtimeActiveWorkspaceURL,
               let projectURL = XcodeInspector.shared.activeProjectRootURL