Show better connection error when using keystore based ssl connection with Tableau connector

With SSL based connection, when keystore path is provided a key store password needs to be supplied as well.

However, in the Tableau connector, the keystore password needs to be passed using a properties file, namely couchbase-analytics.properties (as Tableau does not allow any other secure field other that authentication password), and the file needs to be stored in the Datasources directory. Therefore, a better error should be shown, pointing the user to a page where they can find the steps to provide a keystore password.