* swap-v1

* toggle the version switch based on the search query parameter

* rework some of the query parameter stuff in send/swap

* hide the url when they click it

* allow switching back to v2 via the toggle

* represent the v1 trade in the UI if they toggle it on

* show trade link in both directions (5% threshold for v1 link)

* input amounts should reflect v1/v2

* perform the approve on v1 exchange for v1 trades

* get swap on v1 working

* move some code around to reduce duplication

* fix ts error

* correct input allowance

* fix exact token to token on v1

* fix pending approvals to be specific to the spender

* google analytics for swap version

* disable the version switch on pages other than swap and send