fix: userSeat.hasExited was returning the opposite of its intent

This is mostly test updates, but it fixes one actual bug

fixes: #1729

revive some zoeHelper tests
zoeHelper trade with same handle
Turning eslint back on required cleaning up a bunch of dead code.

packages/zoe/src/contractSupport/zoeHelpers.js

@@ -93,6 +93,12 @@ export const assertIssuerKeywords = (zcf, expected) => {
   );
 };
 
+/**
+ * @typedef {Object} ZcfSeatPartial
+ * @property {() => ProposalRecord} getProposal
+ * @property {() => Allocation} getCurrentAllocation
+ */
+
 /**
  * Check whether an update to currentAllocation satisfies
  * proposal.want. Note that this is half of the offer safety
@@ -101,7 +107,7 @@ export const assertIssuerKeywords = (zcf, expected) => {
  * (update's values prevailing if the keywords are the same)
  * to produce the newAllocation.
  * @param {ContractFacet} zcf
- * @param {ZCFSeat} seat
+ * @param {ZcfSeatPartial} seat
  * @param {AmountKeywordRecord} update
  * @returns {boolean}
  */

packages/zoe/src/zoeService/zoeSeat.js

@@ -88,7 +88,7 @@ export const makeZoeSeatAdminKit = (
     getPayouts: async () => payoutPromiseKit.promise,
     getPayout: async keyword => E.G(payoutPromiseKit.promise)[keyword],
     getOfferResult: async () => offerResult,
-    hasExited: async () => instanceAdmin.hasZoeSeatAdmin(zoeSeatAdmin),
+    hasExited: async () => !instanceAdmin.hasZoeSeatAdmin(zoeSeatAdmin),
     tryExit: async () => E(exitObj).exit(),
     getNotifier: async () => notifier,
   });