[bugfix] Fix a couple accessibility issues with :focus elements (#3979)

* [bugfix/frontend] Fix accessibility/focus issues in settings + web ui

* fix little error

* tweaks

web/template/login_button.tmpl

@@ -18,5 +18,5 @@
 */ -}}
 
 {{- if .showLoginButton }}
-<div class="login"><a href="/login" class="button with-icon">Log in</a></div>
+<div class="login"><a tabindex="0" href="/login" class="button with-icon">Log in</a></div>
 {{- end }}

web/template/status.tmpl

@@ -51,7 +51,13 @@ media photoswipe-gallery {{ (len .) | oddOrEven }} {{ if eq (len .) 1 }}single{{
             <div class="spoiler-content p-summary" lang="{{- .LanguageTag.TagStr -}}">
                 {{ noescape .SpoilerContent | emojify .Emojis }}
             </div>
-            <span class="button" role="button" tabindex="0">Toggle visibility</span>
+            {{- with . }}
+            {{- /*
+                IMPORTANT: Button semantics and aria labels in "button" class below are added in
+                frontend/index.js, as the button doesn't function as a button without javascript.
+            */ -}}
+            {{- end }}
+            <span class="button">Toggle visibility</span>
         </summary>
         <div class="text">
             {{- with . }}

web/template/status_attachment.tmpl

@@ -54,7 +54,13 @@
             {{- end }}
         >
             <div class="show sensitive button" aria-hidden="true">Show sensitive</div>
-            <span class="eye button" role="button" tabindex="0" aria-label="Toggle media visibility">
+            {{- with . }}
+            {{- /*
+                IMPORTANT: Button semantics and aria labels in "eye button" class below are added in
+                frontend/index.js, as the button doesn't function as a button without javascript.
+            */ -}}
+            {{- end }}
+            <span class="eye button">
                 <i class="hide fa fa-fw fa-eye-slash" aria-hidden="true"></i>
                 <i class="show fa fa-fw fa-eye" aria-hidden="true"></i>
             </span>