Refine the colors of some more components (#12343)

* Refine the colors of some more components

This is a reintroduction of https://github.com/matrix-org/matrix-react-sdk/pull/12255, and should be the last part of the Compound color refinement work (https://github.com/element-hq/element-web/issues/26992). I've updated the following components to reflect design decisions (https://www.figma.com/file/pqhlirZFEwEp5XpudSbiia/Theming-Web-templates?type=design&node-id=80-60219&mode=design&t=mjqwylUie1vRwzOV-0) that will help them fit in better with the new design system:

- Message bubbles
- Pills
- Sent indicators
- Jump to bottom/unread buttons
- Composer placeholder
- Notification badges
- Room sublists
- Verification shields
- Date separators
- Tooltips

Closes https://github.com/element-hq/element-web/issues/22122

* Update some screenshots

res/css/views/elements/_Pill.pcss

@@ -26,7 +26,7 @@ limitations under the License.
     overflow: hidden;
     cursor: pointer;
 
-    color: $accent-fg-color !important; /* To override .markdown-body */
+    color: var(--cpd-color-text-on-solid-primary) !important; /* To override .markdown-body */
     background-color: $pill-bg-color !important; /* To override .markdown-body */
 
     > * {
@@ -35,7 +35,7 @@ limitations under the License.
 
     &.mx_UserPill_me,
     &.mx_AtRoomPill {
-        background-color: $alert !important; /* To override .markdown-body */
+        background-color: var(--cpd-color-bg-critical-primary) !important; /* To override .markdown-body */
     }
 
     &:hover {
@@ -43,12 +43,14 @@ limitations under the License.
     }
 
     &.mx_UserPill_me:hover {
-        background-color: #ff6b75 !important; /* To override .markdown-body | same on both themes */
+        background-color: var(
+            --cpd-color-bg-critical-hovered
+        ) !important; /* To override .markdown-body | same on both themes */
     }
 
     /* We don't want to indicate clickability */
     &.mx_AtRoomPill:hover {
-        background-color: $alert !important; /* To override .markdown-body */
+        background-color: var(--cpd-color-bg-critical-primary) !important; /* To override .markdown-body */
         cursor: unset;
     }