'help' rpc commands autocomplete

Adds autocompletion of the commands for when getting the help of a command by using `help <command>`

src/qt/rpcconsole.cpp

@@ -626,9 +626,12 @@ void RPCConsole::setClientModel(ClientModel *model)
         for (size_t i = 0; i < commandList.size(); ++i)
         {
             wordList << commandList[i].c_str();
+            wordList << ("help " + commandList[i]).c_str();
         }
 
+        wordList.sort();
         autoCompleter = new QCompleter(wordList, this);
+        autoCompleter->setModelSorting(QCompleter::CaseSensitivelySortedModel);
         ui->lineEdit->setCompleter(autoCompleter);
         autoCompleter->popup()->installEventFilter(this);
         // Start thread to execute RPC commands.