12175 rack with starting unit > 1 (#12778)

* 12175 add rack starting unit

* 12175 rack starting unit to svg

* verify devices can still fit if change rack starting_unit

* 12175 fix migration

* 12175 fix typo and test

* 12175 fix test

* 12175 fix max height calc display

* Misc cleanup & fixes

---------

Co-authored-by: Jeremy Stretch <jstretch@netboxlabs.com>

netbox/templates/dcim/rack.html

@@ -101,6 +101,12 @@
                         <th scope="row">Height</th>
                         <td>{{ object.u_height }}U ({% if object.desc_units %}descending{% else %}ascending{% endif %})</td>
                     </tr>
+                    <tr>
+                        <th scope="row">Starting Unit</th>
+                        <td>
+                          {{ object.starting_unit }}
+                        </td>
+                    </tr>
                     <tr>
                         <th scope="row">Outer Width</th>
                         <td>

netbox/templates/dcim/rack_edit.html

@@ -71,6 +71,7 @@
         </div>
         {% render_field form.mounting_depth %}
         {% render_field form.desc_units %}
+        {% render_field form.starting_unit %}
     </div>
 
     {% if form.custom_fields %}