feat: password reset (#179) (#186)

* feat: password reset via symfonycasts/reset-password-bundle (#179)

Implements the full password reset flow using the SymfonyCasts reset-password-bundle.

* ci: share base layer cache between dev and prod builds

* fix: use CSS form selector in tests instead of translated button text

* fix: translate missing validator string for reset password email field

* fix: translate reset password form labels via TranslatorInterface

* ci: override MAILER_DSN to null for PHPUnit so mailer host is not required

templates/backoffice/login/login.html.twig

@@ -4,7 +4,7 @@
 
 {% block body %}
     <form method="post">
-        <h1 class="py-2 h3 mb-3 font-weight-normal">{{ 'Please sign in'|trans }}</h1>
+        <h3 class="mb-3">{{ 'Please sign in'|trans }}</h3>
         <div class="mb-3">
             <label for="username" class="form-label">{{ 'Email'|trans }}</label>
             <input type="email" value="{{ last_username }}" name="_username" id="username" class="form-control"
@@ -31,5 +31,7 @@
         </button>
         <a href="{{ path('tvdt_register') }}"
            class="btn btn-link">{{ 'Create an account'|trans }}</a>
+        <a href="{{ path('tvdt_forgot_password_request') }}"
+           class="btn btn-link">{{ 'Forgot your password?'|trans }}</a>
     </form>
 {% endblock %}