Replaced OS beep with current theme's callword sound

NOTE: If the theme points to the wrong sound, it'll still fail to play.

Author: TrickyLeifa

data/ui/options_dialog.ui

@@ -654,7 +654,7 @@
        <item row="3" column="0" colspan="2">
         <widget class="QLabel" name="callwords_sfx_explain">
          <property name="text">
-          <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;When a callword is triggered, the sound provided will be played instead of a general alert beep.&lt;/p&gt;&lt;p&gt;If the sound's filepath is invalid, a general alert beep will be played instead.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+          <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;When a callword is triggered, the sound provided will be played instead of a general alert beep.&lt;/p&gt;&lt;p&gt;If the sound's filepath is invalid, the current theme's callword sound will be played instead.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
          </property>
          <property name="wordWrap">
           <bool>true</bool>

src/courtroom.cpp

@@ -3428,7 +3428,7 @@ void Courtroom::handle_callwords()
       }
       else
       {
-        qApp->beep();
+        modcall_player->findAndPlaySfx(ao_app->get_court_sfx("word_call"));
       }
 
       // Make the window flash