Add frontend qgl query for coursebook documentations

aleksis/apps/alsijil/frontend/components/coursebook.graphql

+query gqlDocumentationsForCoursebook($courseId: ID!, $dateStart: Date!, $dateEnd: Date!) {
+  documentationsForCoursebook(courseId: $courseId, dateStart: $dateStart, dateEnd: $dateEnd) {
+    id
+    course {
+      id
+    }
+    lessonEvent {
+      id
+    }
+    subject {
+      id
+      name
+      shortName
+    }
+    topic
+    homework
+    groupNote
+    datetimeStart
+    datetimeEnd
+    dateStart
+    dateEnd
+  }
+}