fix templates: fix table width issue in download errors and validation

The URL column in the Download Errors page has some very long URLs and
as a result the table overflows its container.  This fix sets the
column width to a maximum and clips any overflowing content.  This fix
has also been pre-emptively applied to the validation page.

iati_dashboard/templates/download.html

@@ -22,7 +22,7 @@ <h2 class="dashboard-panel-heading__title float-start">List of files that fail t
               <tr>
                 <th>Publisher</th>
                 <th>Registry Dataset</th>
-                <th>URL</th>
+                <th style="max-width: 400px; overflow: clip;">URL</th>
                 <th><a href="https://everything.curl.dev/usingcurl/returns">Error Code</a></th>
               </tr>
             </thead>
@@ -31,7 +31,7 @@ <h2 class="dashboard-panel-heading__title float-start">List of files that fail t
               <tr>
                 <td><a href="{{ url('dash-headlines-publisher-detail', args=[publisher]) }}">{{ publisher }}</a></td>
                 <td><a href="http://iatiregistry.org/dataset/{{ dataset }}">{{ dataset }}</a></td>
-                <td><a href="{{ err_url }}">{{ err_url|url_to_filename }}</a></td>
+                <td style="max-width: 400px; overflow: clip;"><a href="{{ err_url }}">{{ err_url|url_to_filename }}</a></td>
                 <td>{{ code }}</td>
               </tr>
               {% endfor %}

iati_dashboard/templates/validation.html

@@ -27,7 +27,7 @@ <h4><a href="{{ url('dash-headlines-publisher-detail', args=[publisher]) }}" id=
             <thead>
               <tr>
                 <th scope="col">Dataset</th>
-                <th scope="col">URL</th>
+                <th style="max-width: 300px; overflow: clip;" scope="col">URL</th>
                 <th scope="col">Validator report</th>
               </tr>
             </thead>
@@ -36,7 +36,7 @@ <h4><a href="{{ url('dash-headlines-publisher-detail', args=[publisher]) }}" id=
             {% with dataset_name=dataset %}
               <tr>
                 <td><a href="http://iatiregistry.org/dataset/{{ dataset_name }}">{{ dataset_name }}</a></td>
-                <td>
+                <td style="max-width: 300px; overflow: clip;">
                   {% if publisher in ckan and dataset_name in ckan[publisher] %}
                   <a href="{{ ckan[publisher][dataset_name].resource.url }}">{{ ckan[publisher][dataset_name].resource.url|url_to_filename }}</a>
                   {% endif %}