add twig templates for error page

modules/core/templates/no_metadata.twig

+<p>{{ '{core:no_metadata:config_problem}' | trans }}</p>
+
+<ul>
+    <li>{{ '{core:no_metadata:suggestion_user_link}' | trans }}</li>
+    <li>{{ '{core:no_metadata:suggestion_developer}' | trans }}</li>
+</ul>
+

modules/core/templates/no_state.twig

+<h3>{{ '{core:no_state:suggestions}' | trans }}</h3>
+<ul>
+    <li>{{ '{core:no_state:suggestion_goback}' | trans }}</li>
+    <li>{{ '{core:no_state:suggestion_closebrowser}' | trans }}</li>
+</ul>
+
+<h3>{{ '{core:no_state:causes}' | trans }}</h3>
+<ul>
+    <li>{{ '{core:no_state:cause_backforward}'  | trans }}</li>
+    <li>{{ '{core:no_state:cause_openbrowser}'  | trans }}</li>
+    <li>{{ '{core:no_state:cause_nocookie}'  | trans }}</li>
+</ul>

templates/error.twig

+
+{% set pagetitle = 'Logged out'|trans %}
+{% extends "base.twig" %}
+
+{% block postload %}
+    <script type="text/javascript">
+        new Clipboard('.clipboard-btn');
+    </script>
+{% endblock %}
+
+{% block content %}
+    <h2>{{ dictTitle | trans }}</h2>
+    {{ dictDescr | trans(parameters) }}
+
+    {# include optional information for error
+       Some excepltions set 'incluseTemplate' to the name of a template to include.
+       e.g. "core:no_state.tpl.php". The format is "<module>:<template name>"
+    #}
+    {% if includeTemplate %}
+        {% include(includeTemplate) %}
+    {% endif %}
+
+    {# TODO: Update class #}
+    <div class="metadatabox">
+        <p>{{ '{errors:report_trackid}' | trans }}</p>
+        {# TODO: Update class #}
+        <div class="">
+            <pre id="trackid">{{ error.trackId }}</pre>
+            <button data-clipboard-target="#trackid" id="btntrackid" class="clipboard-bnt pure-button left clipboard-btn">
+                <i class="fa fa-copy"></i>
+            </button>
+        </div>
+    </div>
+
+    {# print out exception only if the exception is available #}
+    {% if showerrors %}
+        <h2>{{'{errors:debuginfo_header}' | trans}}</h2>
+        <p>{{'{errors:debuginfo_text}' | trans}}</p>
+
+        {# TODO: Update class #}
+        <div class="metadatabox">
+            <pre>{{ error.exceptionMsg }}</pre>
+            <pre>{{ error.exceptionTrace }}</pre>
+        </div>
+    {% endif %}
+
+    {# Add error report submit section if we have a valid technical contact. 'errorreportaddress' will only be set if
+       the technical contact email address has been set. #}
+    {% if errorReportAddress %}
+        <h2>{{ '{errors:report_header}' | trans }}</h2>
+        <form action="{{ errorReportAddress }}" method="post">
+            <p>{{ '{errors:report_text}' | trans }}</p>
+            <p>{{ '{errors:report_email}' | trans }}
+                <input type="email" name="email" value="{{ email }}" />
+            </p>
+            <p>
+                <textarea class="metadatabox" name="text" rows="6" cols="50">{{ '{errors:report_explain}' | trans }}</textarea>
+            </p>
+        </form>
+        <p>
+            <input type="hidden" name="reportId" value="{{ error.reportId }}" />
+            <button type="submit" name="send" class="btn">{{ '{errors:report_submit}' | trans }}</button>
+        </p>
+    {% endif %}
+
+    <h2>{{ '{errors:howto_header}' | trans }}</h2>
+    <p>{{ '{errors:howto_text}' | trans }}</p>
+
+{% endblock %}
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