rework: make the filter as a tabbed widget in the dialog itself

Still needs a clear indication that the filter only applies after you
click the search button...

launcher/ui/pages/modplatform/ModPage.ui

@@ -11,7 +11,7 @@
    </rect>
   </property>
   <layout class="QGridLayout" name="gridLayout">
-   <item row="1" column="0" colspan="2">
+   <item row="1" column="0" colspan="4">
     <layout class="QGridLayout" name="gridLayout_3">
      <item row="1" column="2">
       <widget class="QTextBrowser" name="packDescription">
@@ -41,7 +41,7 @@
      </item>
     </layout>
    </item>
-   <item row="0" column="1">
+   <item row="0" column="3">
     <widget class="QPushButton" name="searchButton">
      <property name="text">
       <string>Search</string>
@@ -55,7 +55,7 @@
      </property>
     </widget>
    </item>
-   <item row="2" column="0" colspan="2">
+   <item row="2" column="0" colspan="4">
     <layout class="QGridLayout" name="gridLayout_4" columnstretch="0,0,0">
      <item row="0" column="2">
       <widget class="QComboBox" name="versionSelectionBox"/>
@@ -80,15 +80,22 @@
        </property>
       </widget>
      </item>
-     <item row="1" column="0">
-      <widget class="QPushButton" name="modFilterButton">
-       <property name="text">
-        <string>Filter options</string>
-       </property>
-      </widget>
-     </item>
     </layout>
    </item>
+   <item row="0" column="1">
+    <widget class="QPushButton" name="modFilterButton">
+     <property name="text">
+      <string>Filter options</string>
+     </property>
+    </widget>
+   </item>
+   <item row="0" column="2">
+    <widget class="Line" name="line">
+     <property name="orientation">
+      <enum>Qt::Vertical</enum>
+     </property>
+    </widget>
+   </item>
   </layout>
  </widget>
  <tabstops>