Revert "keeping cache of pending requests for 10 seconds, in case another panel makes the same es query", since it seems queries over longer periods of time actually do multiple requests/responses

This reverts commit 8b81e91df63db9f26610ca117339f0070ad208f7.
Revert "use the same timestamp for requests between refreshes"

This reverts commit c0c4fd1511462457e089131d77da9134d61adc89.