Revert "Member avatars without canvas" (#10057

* Revert "Apply more general fix for base avatar regressions (#10045)"

This reverts commit 371a3c0d36.

* Revert "Fix layout and visual regressions around default avatars (#10031)"

This reverts commit 0d1fce37b2.

* Revert "Member avatars without canvas (#9990)"

This reverts commit a8aa4de4b4.

* Update snapshots

test/components/views/right_panel/__snapshots__/RoomSummaryCard-test.tsx.snap

@@ -22,16 +22,22 @@ exports[`<RoomSummaryCard /> renders the room summary 1`] = `
         <span
           class="mx_BaseAvatar"
           role="presentation"
-          style="width: 54px; height: 54px;"
         >
           <span
             aria-hidden="true"
-            class="mx_BaseAvatar_image mx_BaseAvatar_initial"
-            data-testid="avatar-img"
-            style="background-color: rgb(13, 189, 139); width: 54px; height: 54px; font-size: 35.1px; line-height: 54px;"
+            class="mx_BaseAvatar_initial"
+            style="font-size: 35.1px; width: 54px; line-height: 54px;"
           >
             !
           </span>
+          <img
+            alt=""
+            aria-hidden="true"
+            class="mx_BaseAvatar_image"
+            data-testid="avatar-img"
+            src="data:image/png;base64,00"
+            style="width: 54px; height: 54px;"
+          />
         </span>
         <div
           class="mx_TextWithTooltip_target mx_RoomSummaryCard_e2ee"