Docs: invoke_search_popup uses bl_property

Also add code example in docs.

doc/python_api/examples/bpy.types.Operator.6.py

@@ -0,0 +1,38 @@
+"""
+Enum Search Popup
++++++++++++++++++
+
+You may want to have an operator prompt the user to select an item
+from a search field, this can be done using :class:`bpy.types.Operator.invoke_search_popup`.
+"""
+import bpy
+from bpy.props import EnumProperty
+
+
+class SearchEnumOperator(bpy.types.Operator):
+    bl_idname = "object.search_enum_operator"
+    bl_label = "Search Enum Operator"
+    bl_property = "my_search"
+
+    my_search = EnumProperty(
+        name="My Search",
+        items=(
+            ('FOO', "Foo", ""),
+            ('BAR', "Bar", ""),
+            ('BAZ', "Baz", ""),
+        ),
+    )
+
+    def execute(self, context):
+        self.report({'INFO'}, "Selected:" + self.my_search)
+        return {'FINISHED'}
+
+    def invoke(self, context, event):
+        context.window_manager.invoke_search_popup(self)
+        return {'RUNNING_MODAL'}
+
+
+bpy.utils.register_class(SearchEnumOperator)
+
+# test call
+bpy.ops.object.search_enum_operator('INVOKE_DEFAULT')