Ui improvements (#6198)

* PLT-6306 - Post alignment in compact view

* PLT-6266 - Adjusting spacing for files (compact)

* PLT-6302 - Margins not equal for paragraphs in post

* PLT-6332 - FIxing inline images

* PLT-6134 - Fixing border on emoji picker

* PLT-6323 - Fixing UI for system console user list

* PLT-6375 - Updating emoji picker

* PLT-6327 - Updating more channel/user list

* PLT-6241 - Adding IE detection

* PLT-6332- Fixing inline markdown images

webapp/sass/layout/_content.scss

@@ -67,13 +67,6 @@
     }
 }
 
-#post-create {
-    @include flex(0 0 auto);
-    background: $white;
-    width: 100%;
-    z-index: 3;
-}
-
 #archive-link-home {
     @include flex(0 0 auto);
     cursor: pointer;