feat(connections): If EmailEngine is syncing an account then use a secondary IMAP connection to serve API requests

Author: andris9

lib/account.js

@@ -395,18 +395,24 @@ class Account {
         }
 
         let accountData = this.unserializeAccountData(result);
-        if (requireValid && accountData.state !== 'connected') {
+        if (requireValid && !['connected', 'connecting', 'syncing'].includes(accountData.state)) {
             let err;
             switch (accountData.state) {
                 case 'init':
                     err = new Error('Requested account is not yet initialized');
                     err.code = 'NotYetConnected';
                     break;
+                /*
+                // Check disabled for the following states - allow commands to go through.
+                // A secondary IMAP connection is opened if possible.
+                */
+                /*
                 case 'connecting':
                 case 'syncing':
                     err = new Error('Requested account is not yet connected');
                     err.code = 'NotYetConnected';
                     break;
+                */
                 case 'authenticationError':
                     err = new Error('Requested account can not be authenticated');
                     err.code = 'AuthenticationFails';