work on select_experiment

- on currently running exp. make two links, to instrument
  or history only
- create dummy secop client when hideRightPart is used in order
  to avoid waiting impossible connection

client/jsFiles/SEAWebClientMain.js

@@ -84,6 +84,7 @@ if (window.instrument) {
     let args = '';
     if (window.stream) { args += "&stream=" + window.stream; }
     if (window.device) { args += "&device=" + window.device; }
+    if (window.hideRightPart) { args += "&history_only=1"; }
     window.clientTags = args;
 }