feat: use images.AutoOrient in helper/image (#1294)

* feat: use images.AutoOrient in `helper/image`

closes https://github.com/CaiJimmy/hugo-theme-stack/issues/1292

* fix: check if IsImageResourceProcessable before using filter

* remove local field

* feat: add configurable image auto-orientation via a new `autoOrient` parameter in site configuration

layouts/_partials/sidebar/left.html

@@ -7,7 +7,7 @@
 
     <header>
         {{ with .Site.Params.sidebar.avatar }}
-            {{- $avatar := partial "helper/image" (dict "Image" . "Resources" resources) -}}
+            {{- $avatar := partial "helper/image" (dict "Image" . "Resources" resources "Context" $) -}}
             <figure class="site-avatar">
                 <a href="{{ $.Site.Home.RelPermalink }}">
                     <img src="{{ $avatar.Permalink }}"