[Feature] Implement Search modal in Modern UI (#185)

Implementing a search modal (stretching the level of dynamic that is possible without going to frameworks).

## Major Change
- Search needs packages and is available everywhere now; so had to add reviewed and user packages to global context.

Co-authored-by: Tim Lorsbach <tim@lorsba.ch>
Reviewed-on: enviPath/enviPy#185
Co-authored-by: Tobias O <tobias.olenyi@envipath.com>
Co-committed-by: Tobias O <tobias.olenyi@envipath.com>

templates/framework.html

@@ -286,7 +286,6 @@
 </script>
 {% block modals %}
     {% include "modals/cite_modal.html" %}
-    {% include "modals/signup_modal.html" %}
     {% include "modals/predict_modal.html" %}
     {% include "modals/batch_predict_modal.html" %}
 {% endblock %}