Synchronously update transaction status (#8563)

All transaction status updates were moved into a `setTimeout` callback
and wrapped in a `try...catch` block in #4131, apparently in an attempt
to prevent failures in event subscribers from interrupting the
transaction logic. The `try...catch` block did accomplish that, but by
putting the status update in a `setTimeout` callback the operation was
made asynchronous.

Transaction status updates now happen unpredictably, in some future
event loop from when they're triggered. This creates a race condition,
where the transaction status update may occur before or after
subsequent state changes. This also introduces a risk of accidentally
undoing a change to the transaction state, as the update made to the
transaction inside the `setTimeout` callback uses a reference to
`txMeta` obtained synchronously before the `setTimeout` call. Any
replacement of the `txMeta` between the `setTxStatus` call and the
execution of the timeout would be erased. Luckily the `txMeta` object
is more often than not mutated rather than replaced, which may explain
why we haven't seen this happen yet.

Everything seems to work correctly with the `setTimeout` call removed,
and now the transaction logic is easier to understand.

app/scripts/controllers/transactions/tx-state-manager.js

@@ -455,19 +455,17 @@ export default class TransactionStateManager extends EventEmitter {
     }
 
     txMeta.status = status
-    setTimeout(() => {
-      try {
-        this.updateTx(txMeta, `txStateManager: setting status to ${status}`)
-        this.emit(`${txMeta.id}:${status}`, txId)
-        this.emit(`tx:status-update`, txId, status)
-        if (['submitted', 'rejected', 'failed'].includes(status)) {
-          this.emit(`${txMeta.id}:finished`, txMeta)
-        }
-        this.emit('update:badge')
-      } catch (error) {
-        log.error(error)
+    try {
+      this.updateTx(txMeta, `txStateManager: setting status to ${status}`)
+      this.emit(`${txMeta.id}:${status}`, txId)
+      this.emit(`tx:status-update`, txId, status)
+      if (['submitted', 'rejected', 'failed'].includes(status)) {
+        this.emit(`${txMeta.id}:finished`, txMeta)
       }
-    })
+      this.emit('update:badge')
+    } catch (error) {
+      log.error(error)
+    }
   }
 
   /**