STTextView: Implement missing accessibility setters

This commit implements the missing setter methods for accessibility properties, allowing VoiceOver and other assistive technologies to control the text view. It adds setters for selected text, selected text ranges, and focus state, which correspond to the existing getter methods.

Author: krzyzanowskim

Sources/STTextViewAppKit/STTextView+NSAccessibilityProtocol.swift renamed to Sources/STTextViewAppKit/STTextView+Accessibility.swift

@@ -44,13 +44,31 @@ extension STTextView  {
         textLayoutManager.textSelectionsString()
     }
 
+    open override func setAccessibilitySelectedText(_ accessibilitySelectedText: String?) {
+        self.replaceCharacters(in: selectedRange(), with: accessibilitySelectedText ?? "")
+    }
+
     open override func accessibilitySelectedTextRange() -> NSRange {
         selectedRange()
     }
 
+    open override func setAccessibilitySelectedTextRanges(_ accessibilitySelectedTextRanges: [NSValue]?) {
+        for range in accessibilitySelectedTextRanges?.map(\.rangeValue) ?? [] {
+            self.setSelectedRange(range)
+        }
+    }
+
     open override func isAccessibilityFocused() -> Bool {
         isFirstResponder && isSelectable
     }
+
+    open override func setAccessibilityFocused(_ accessibilityFocused: Bool) {
+        if !accessibilityFocused, isFirstResponder {
+            window?.makeFirstResponder(nil)
+        } else if accessibilityFocused {
+            window?.makeFirstResponder(self)
+        }
+    }
 }
 
 extension STTextView  {
@@ -130,5 +148,4 @@ extension STTextView  {
     open override func accessibilityString(for range: NSRange) -> String? {
         attributedSubstring(forProposedRange: range, actualRange: nil)?.string
     }
-
 }