feat: add Schematron rule for IIIF (closes #40)

1.1/lido-qa.xsd

@@ -107,6 +107,23 @@
                     </sch:assert>
                 </sch:rule>
             </sch:pattern>
+
+            <sch:pattern>
+                <sch:title>Avoid Providing Resource Measurements When Using IIIF</sch:title>
+                <sch:p>IIIF resources provide information about their measurements in their
+                    info.json. Therefore it is redundant to also make the resource's measurements
+                    available in lido:resourceMeasurementsSet.</sch:p>
+                <sch:rule context="lido:resourceRepresentation" id="IIIF_Measurements">
+                    <sch:assert role="warn"
+                        test="
+                            (@type = 'http://terminology.lido-schema.org/lido00911' or @type = 'http://terminology.lido-schema.org/lido00912')
+                            and not(lido:resourceMeasurementsSet)"
+                        > Do not set lido:resourceMeasurementsSet when providing a IIIF resource.
+                        Resource measurements are available in the resource's info.json.
+                    </sch:assert>
+                </sch:rule>
+            </sch:pattern>
+
         </xs:appinfo>
     </xs:annotation>
 </xs:schema>