Added tests for SiteLinksEditTool value row insertion behavior

When a new value row gets inserted into the SiteLinksEditTool, it will first be inserted into the
tfoot part of the table, so the row won't be affected by table sorting. After the value got saved,
it is supposed to be moved into the tbody section. This behavior is now ensured by these test.

Change-Id: Iad16410be423f3af88dead38fbb51a127a4b4a52
Merge "Added tests for SiteLinksEditTool value row insertion behavior"