Fix: Space scope header overflow (#11933)

* fix spacing for scope header

* extract scope header into component, apply line clamp

* update ThirdPartyMemberInfo styles

* pass onClose to ThirdPartyRoomMemberInfo

* rethemendex

* add View3pidInvite to actions enum, replace uses

* extract out action handler

* push card instead, test

* comment

* reinstate data-testid

* fix typo in styles

res/css/views/rooms/_MemberList.pcss

@@ -42,12 +42,6 @@ limitations under the License.
     .mx_AutoHideScrollbar {
         flex: 1 1 0;
     }
-
-    .mx_RightPanel_scopeHeader {
-        /* vertically align with position on other right panel cards */
-        /* to prevent it bouncing as user navigates right panel */
-        margin-top: -8px;
-    }
 }
 
 .mx_MemberList_chevron {