Continued removal of deprecated or dead code (#7711)

This PR removes the EditorMouseEventService.java and
EditorPositionService.java project services

Continuation of #7710
and #7706

Author: jwren

flutter-idea/src/io/flutter/editor/EditorMouseEventService.java

@@ -679,12 +679,6 @@
     <projectService serviceInterface="io.flutter.editor.ActiveEditorsOutlineService"
                     serviceImplementation="io.flutter.editor.ActiveEditorsOutlineService"
                     overrides="false"/>
-    <projectService serviceInterface="io.flutter.editor.EditorMouseEventService"
-                    serviceImplementation="io.flutter.editor.EditorMouseEventService"
-                    overrides="false"/>
-    <projectService serviceInterface="io.flutter.editor.EditorPositionService"
-                    serviceImplementation="io.flutter.editor.EditorPositionService"
-                    overrides="false"/>
     <projectService serviceInterface="io.flutter.inspector.InspectorGroupManagerService"
                     serviceImplementation="io.flutter.inspector.InspectorGroupManagerService"
                     overrides="false"/>

flutter-idea/src/io/flutter/editor/EditorPositionService.java

@@ -371,12 +371,6 @@
     <projectService serviceInterface="io.flutter.editor.ActiveEditorsOutlineService"
                     serviceImplementation="io.flutter.editor.ActiveEditorsOutlineService"
                     overrides="false"/>
-    <projectService serviceInterface="io.flutter.editor.EditorMouseEventService"
-                    serviceImplementation="io.flutter.editor.EditorMouseEventService"
-                    overrides="false"/>
-    <projectService serviceInterface="io.flutter.editor.EditorPositionService"
-                    serviceImplementation="io.flutter.editor.EditorPositionService"
-                    overrides="false"/>
     <projectService serviceInterface="io.flutter.inspector.InspectorGroupManagerService"
                     serviceImplementation="io.flutter.inspector.InspectorGroupManagerService"
                     overrides="false"/>