- Add more test cases for sequential swap and single swap to match those of split swap (fee, slippage), to catch errors more easily if someone makes a small code change to either the single or sequential methods
- Excluded USV3 and USV4 tests on sequential and single swap, since these tests were more to test USV3 and USV4 executor functionality than the high level sswap methods - they should already be sufficiently tested.
- Remove `testSplitSwapSimple` and `testSplitSwapSingleUSV3` since this is already tested by several other high-level methods (see single USV3 and single USV4 tests). We should prioritize integration-testing public methods over private methods.
