Add some tooltips to diagram show properties

Refs #19109

Author: nyalldawson

src/ui/qgsdiagrampropertiesbase.ui

@@ -844,6 +844,9 @@
                              <verstretch>0</verstretch>
                             </sizepolicy>
                            </property>
+                           <property name="toolTip">
+                            <string>Controls whether specific diagrams should be shown</string>
+                           </property>
                            <property name="text">
                             <string>Show diagram</string>
                            </property>
@@ -871,6 +874,9 @@
                              <verstretch>0</verstretch>
                             </sizepolicy>
                            </property>
+                           <property name="toolTip">
+                            <string>Controls whether specific diagrams should always be rendered, even when they overlap other diagrams or map labels</string>
+                           </property>
                            <property name="text">
                             <string>Always show</string>
                            </property>
@@ -952,6 +958,9 @@
                        </item>
                        <item row="1" column="0" colspan="3">
                         <widget class="QCheckBox" name="mShowAllCheckBox">
+                         <property name="toolTip">
+                          <string>Always show all diagrams, even when they overlap with each other or other map labels</string>
+                         </property>
                          <property name="text">
                           <string>Show all diagrams</string>
                          </property>