add filter line edit to UI

src/ui/symbollayer/widget_svgselector.ui

@@ -38,7 +38,7 @@
       <string>SVG browser</string>
      </property>
      <layout class="QGridLayout" name="gridLayout_2">
-      <item row="0" column="0">
+      <item row="1" column="0">
        <widget class="QSplitter" name="splitter">
         <property name="orientation">
          <enum>Qt::Horizontal</enum>
@@ -129,6 +129,30 @@
         </widget>
        </widget>
       </item>
+      <item row="0" column="0">
+       <layout class="QHBoxLayout" name="horizontalLayout">
+        <item>
+         <spacer name="horizontalSpacer_2">
+          <property name="orientation">
+           <enum>Qt::Horizontal</enum>
+          </property>
+          <property name="sizeHint" stdset="0">
+           <size>
+            <width>40</width>
+            <height>20</height>
+           </size>
+          </property>
+         </spacer>
+        </item>
+        <item>
+         <widget class="QgsFilterLineEdit" name="mSvgFilterLineEdit">
+          <property name="showSearchIcon" stdset="0">
+           <bool>true</bool>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
      </layout>
     </widget>
    </item>
@@ -220,6 +244,11 @@
    <header location="global">qgscollapsiblegroupbox.h</header>
    <container>1</container>
   </customwidget>
+  <customwidget>
+   <class>QgsFilterLineEdit</class>
+   <extends>QLineEdit</extends>
+   <header>qgsfilterlineedit.h</header>
+  </customwidget>
  </customwidgets>
  <resources>
   <include location="../../../images/images.qrc"/>