[Fix] Mitigate XSS attack vector by cleaning input before it hits our Database (#171)

## Changes

- All text input fields are now cleaned with nh3 to remove html tags. We allow certain html tags under `settings.py/ALLOWED_HTML_TAGS` so we can easily update the tags we allow in the future.
- All names and descriptions now use the template tag `nh_safe` in all html files.
- Usernames and emails are a small exception and are not allowed any html tags

Co-authored-by: Liam Brydon <62733830+MyCreativityOutlet@users.noreply.github.com>
Co-authored-by: jebus <lorsbach@envipath.com>
Co-authored-by: Tim Lorsbach <tim@lorsba.ch>
Reviewed-on: enviPath/enviPy#171
Reviewed-by: jebus <lorsbach@envipath.com>
Co-authored-by: liambrydon <lbry121@aucklanduni.ac.nz>
Co-committed-by: liambrydon <lbry121@aucklanduni.ac.nz>

templates/modals/collections/new_pathway_modal.html

@@ -1,3 +1,4 @@
+
 {% load static %}
 <div class="modal fade" tabindex="-1" id="new_pathway_modal" role="dialog" aria-labelledby="new_pathway_modal"
      aria-hidden="true" style="overflow-y: auto;">
@@ -111,7 +112,7 @@
 
                     <select id="settingSelect" name="settingSelect" class="form-control">
                         {% for setting in available_settings %}
-                        <option value="{{ setting.id }}">{{ setting.name }}</option>
+                        <option value="{{ setting.id }}">{{ setting.name|safe }}</option>
                         {% endfor %}
                     </select>
                     <p></p>