ENH: added stub for data analysis module

src/core/js/ext_data_analysis.js

+
+function runCorrAnalysis(entity_id) {
+    console.log(entity_id);
+    connection.runScript("", {"-Oentity": entity_id});
+}
+
+var ents = getEntities();
+for (ent of ents) {
+    var parents = getParents(ent);
+    if (parents.length > 0 && parents[0].name == "") {
+	var button = $("<button>Data Analysis</button>");
+	button.click((function(entity_id){return()=>runCorrAnalysis(entity_id);})(getEntityID(ent)));
+	$(ent).find(".caosdb-v-entity-header-buttons-list").prepend(button);
+    }
+}