[GM3Restyling] Make snapshot name editable

This fixes a bug that we introduced with style changes in the Memory
Panel, where the name of the snapshot was no longer editable.

Bug: 319441690
Change-Id: Ib6f1b3aa52d9155bd140c14da584e63c77734740
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/5683043
Reviewed-by: Kateryna Prokopenko <kprokopenko@chromium.org>
Commit-Queue: Kim-Anh Tran <kimanh@chromium.org>

front_end/panels/profiler/profilesSidebarTree.css

@@ -175,6 +175,7 @@ li .titles {
 }
 
 li .titles > .title-container {
+ z-index: 1;
  text-overflow: ellipsis;
  overflow: hidden;
 }