Admin Section: misc templates corrections and improvments

* reset admin vertical menu custom styles
* disable icons in admin vertical menu
* fix main content positioning in admin section
* fix table appearance in admin crud template
* new scope/center form: move submit button in record_action sticky area
* edit scope/center form: move submit button in record_action sticky area
* improve homogeneity in admin index pages: centers/scopes/users/jobs
* remove centered div old tags

src/Bundle/ChillMainBundle/Resources/public/chill/chillmain.scss

@@ -220,12 +220,8 @@ footer.footer {
  */
 
  div.admin {
-   flex-direction: row-reverse;
    div.vertical-menu {
-      font-size: 0.9em;
-      .list-group-item {
-         padding: 0.3rem 0.7rem;
-      }
+      .list-group-item {}
    }
  }
 
@@ -367,6 +363,19 @@ div#flashMessages {
     }
 }
 
+/// unbullet lists
+ul.unbullet {
+    list-style-type: none;
+    padding-left: 0;
+}
+/// libellé
+span.dt {
+    font-size: 90%;
+    font-weight: bolder;
+    background-color: var(--bs-chill-light-gray);
+}
+
+
 /*
  *    SPECIFIC RULES
  */