Add options to leave junctions and contact blocks out of the parts list (#1178)

Since #849 the parts list has a row for every contact block (slave) and
terminal-type element. Users who draw the dots and bends where wires
branch as terminal-type symbols (114_connections) get one empty row per
junction: 109 of 151 rows on one reported cabinet.

Two options, both off by default so existing exports are unchanged:
- leave out the contact blocks: --no-slaves, "no_slaves" in qet_export,
  or uncheck the new "Contacts esclaves" element type in the dialog;
- leave out the junctions: terminal-type elements with no label,
  designation, manufacturer or manufacturer reference. --no-junctions,
  "no_junctions", or "Laisser de côté les jonctions" in the dialog.
  A terminal block with a label or a part number stays.

The element type filter had no box for slaves, so every query it built
left them out: the export dialog never listed contact blocks, although
the command line has since #849. The dialog now checks the new box by
default and gives the same rows as --export-bom. The box is unchecked by
default elsewhere, so nomenclature tables keep their rows.

docs/smart-device-bom.md still said slaves and terminals were excluded;
corrected.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

sources/dataBase/ui/elementquerywidget.ui

@@ -318,6 +318,16 @@
             </property>
            </widget>
           </item>
+          <item row="4" column="0">
+           <widget class="QCheckBox" name="m_slave_cb">
+            <property name="text">
+             <string>Contacts esclaves</string>
+            </property>
+            <property name="checked">
+             <bool>false</bool>
+            </property>
+           </widget>
+          </item>
          </layout>
         </widget>
       </item>