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/rooms/_MessageComposer.pcss

@@ -191,7 +191,7 @@ limitations under the License.
 }
 
 .mx_MessageComposer_button {
-    @mixin composerButton 50%, var(--cpd-color-icon-secondary), var(--cpd-color-bg-subtle-secondary);
+    @mixin composerButton 50%, var(--cpd-color-icon-primary), var(--cpd-color-bg-subtle-primary);
 
     &:last-child {
         margin-right: auto;