Devtools: PM4 Explorer (#1094)

* Devtools: Pause system

* Devtools: pm4 viewer

- new menu bar
- refactored video_info layer
- dump & inspect pm4 packets
- removed dumpPM4 config
- renamed System to DebugState
- add docking space
- simple video info constrained to window size

* Devtools: pm4 viewer - add combo to select the queue

* Devtools: pm4 viewer - add hex editor

* Devtools: pm4 viewer - dump current cmd

* add monospaced font to devtools

* Devtools: pm4 viewer - use spec op name

avoid some allocations

src/qt_gui/settings_dialog.ui

@@ -664,13 +664,6 @@
                  </property>
                 </widget>
                </item>
-               <item>
-                <widget class="QCheckBox" name="dumpPM4CheckBox">
-                 <property name="text">
-                  <string>Enable PM4 Dumping</string>
-                 </property>
-                </widget>
-               </item>
               </layout>
              </widget>
             </item>