PLT-6905 - Updating channel header design (#6789)

* PLT-6905 - Updating channel header design

* Updating border-radius

* Updating radius for wide icons

* Updating trigger for overlay

* Updating UI for channel header

* Updating channel header sizing

* Updating channel header css

* Updating sidebar css

* Updating status icons

* Adjusting border

* Updating comment

* Removing type from status icon

* Fixing UI issues for the channel header/sidebar

* make "Add a channel description" open the channel header modal

* Updating status and opacity

* Updating stauts icon positioning

* Updating description and heading size

* Updating UI changes

* Updating UI changes

* add a focused class to the parent div .search__form and then remove when hover away

* Fix active state for pinned posts icon

* Updating UI changes

* Update channel header text

webapp/sass/layout/_post.scss

@@ -1487,16 +1487,21 @@
 
     .flag-icon__container {
         display: inline-block;
-        font-size: 12px;
+        height: 15px;
         margin-left: 7px;
         position: relative;
-        top: 1px;
+        top: 2px;
+        vertical-align: top;
         visibility: hidden;
 
         &.visible {
             visibility: visible;
         }
 
+        svg {
+            width: 12px;
+        }
+
         path {
             fill: inherit;
         }