feat: use searchable themed translation language picker

Sources/Conjure/TranslationController.swift

@@ -220,23 +220,15 @@ final class TranslationController: NSViewController {
     }
 
     private func chooseLanguage(source: Bool) {
-        let menu = NSMenu(title: source ? "Source language" : "Target language")
-        for code in Self.languages {
-            let item = NSMenuItem(title: languageName(code), action: #selector(languageSelected(_:)), keyEquivalent: "")
-            item.target = self
-            item.representedObject = code
-            item.tag = source ? 0 : 1
-            item.state = code == (source ? sourceLanguage : targetLanguage) ? .on : .off
-            menu.addItem(item)
+        actions.selectLanguage = { [weak self] code in
+            guard let self else { return }
+            self.setLanguages(source: source ? code : self.sourceLanguage,
+                              target: source ? self.targetLanguage : code)
         }
-        menu.popUp(positioning: menu.items.first { $0.state == .on },
-                   at: NSPoint(x: 0, y: languageButton.bounds.maxY), in: languageButton)
-    }
-
-    @objc private func languageSelected(_ item: NSMenuItem) {
-        guard let code = item.representedObject as? String else { return }
-        setLanguages(source: item.tag == 0 ? code : sourceLanguage,
-                     target: item.tag == 1 ? code : targetLanguage)
+        actions.showLanguages(Self.languages.map { (code: $0, name: languageName($0)) },
+                              selected: source ? sourceLanguage : targetLanguage,
+                              source: source, relativeTo: actionsButton)
+        translateButton.keyEquivalent = actions.isShown ? "" : "\r"
     }
 
     func setLanguages(source: String, target: String) {