Update flag tab after new review site tab is complete

[cristinamullin]

Describe the solution you'd like

This issue cannot be completed until #149 and #136 are completed.

This issue could then be addressed. Note that @triphook who is the original developer of the flag tab and can help answer any follow up questions related to this issue.

TADA_FlagCoordinates() is run on the flag tab and there are two rows (outside US and imprecise) there that will become duplicative of functionality on the new Site Review tab once complete. These can be removed from the flag tab at that point.

In addition, the flag tab name should be updated to "Flag Sites" so the name is different from the new "Flag Sites" tab.