Fix encypt/decrypt tx queueing (#10350)

Fixes #10231

Use unconfirmedTransactionsListSelector in the encypt/decrypt components to render the appropriate data to the component at the appropriate time(?).
I am still unsure how sometimes the state.confirmTransaction can we left empty sometimes on rendering the component, possibly the issue with the ConfirmTransaction componentDidUpdate constantly hitting this section.
https://github.com/MetaMask/metamask-extension/blob/develop/ui/app/pages/confirm-transaction/confirm-transaction.component.js#L94-L101

For now this seems to be an intermediate fix.

ui/app/pages/confirm-decrypt-message/confirm-decrypt-message.container.js

@@ -10,6 +10,7 @@ import {
 } from '../../store/actions';
 import {
   getTargetAccountWithSendEtherInfo,
+  unconfirmedTransactionsListSelector,
   conversionRateSelector,
 } from '../../selectors';
 import { clearConfirmTransaction } from '../../ducks/confirm-transaction/confirm-transaction.duck';
@@ -18,11 +19,12 @@ import ConfirmDecryptMessage from './confirm-decrypt-message.component';
 
 function mapStateToProps(state) {
   const {
-    confirmTransaction,
     metamask: { domainMetadata = {} },
   } = state;
 
-  const { txData = {} } = confirmTransaction;
+  const unconfirmedTransactions = unconfirmedTransactionsListSelector(state);
+
+  const txData = unconfirmedTransactions[0];
 
   const {
     msgParams: { from },

ui/app/pages/confirm-encryption-public-key/confirm-encryption-public-key.container.js

@@ -10,6 +10,7 @@ import {
 
 import {
   conversionRateSelector,
+  unconfirmedTransactionsListSelector,
   getTargetAccountWithSendEtherInfo,
 } from '../../selectors';
 
@@ -19,11 +20,12 @@ import ConfirmEncryptionPublicKey from './confirm-encryption-public-key.componen
 
 function mapStateToProps(state) {
   const {
-    confirmTransaction,
     metamask: { domainMetadata = {} },
   } = state;
 
-  const { txData = {} } = confirmTransaction;
+  const unconfirmedTransactions = unconfirmedTransactionsListSelector(state);
+
+  const txData = unconfirmedTransactions[0];
 
   const { msgParams: from } = txData;