[IMP] web_editor, website(_*): show all snippets even if module is not installed

* mail_channel, mass_mailing, twitter, event

- t-install attribute holds the technical name of the module that
  needs to be install to use a particular snippet.

- Disable the drag & drop feature for these dummy snippets.

- Move some images to website module.

- Installed snippets display at the top of the list.

- Hide not-installed module snippets if user don't have rights to install module.

1 files changed, 15 insertions, 0 deletions

diff --git a/addons/web_editor/static/src/less/web_editor.ui.less b/addons/web_editor/static/src/less/web_editor.ui.less
index 4f1eb7dc4be..f83a73984c4 100644
--- a/addons/web_editor/static/src/less/web_editor.ui.less
+++ b/addons/web_editor/static/src/less/web_editor.ui.less
@@ -86,6 +86,8 @@ html[lang] > body.editor_enable [data-oe-translation-state] {
 
 // SNIPPET PANEL
 #oe_snippets {
+    .o-w-preserve-btn();
+
     .o-flex-display();
     .o-flex-flow(column, nowrap);
     .o-position-absolute(0, auto, 0, -@o-we-sidebar-width);
@@ -173,6 +175,19 @@ html[lang] > body.editor_enable [data-oe-translation-state] {
                     }
                 }
 
+                &.o_snippet_install {
+                    .oe_snippet_thumbnail_img {
+                        opacity: 0.5;
+                    }
+                    .btn.o_install_btn {
+                        display: none;
+                        .o-position-absolute(16px, 4px, auto, 4px);
+                    }
+                    &:hover .btn.o_install_btn {
+                        display: block;
+                    }
+                }
+
                 &:nth-child(2n+1) {
                     clear: left;
                 }