[pgAdmin4][Patch]: RM#1268 - Add a Help button to the bottom left of the Wizard framework

Hi,

Please find the patch with following changes:
1. Added help button to the bottom left of the wizard framework.
*Usage: *
Set *wizard_help* property with url while creating wizard object.

var wizard = new (pgBrowser.Wizard.extend({
options: {
title: _('Wizard Title'),
* wizard_help: "{{ url_for('help.static', filename='grant_wizard.html')
}}"*
}
})

2. Previously wizard progress bar was in bottom left of the wizard
framework in place of help button.
So, It is now moved to top of Wizard page.

3. Added class *col-xs-** to the wizard div to be more consistent.

4. Set proper height for *wizard-right-panel_content* in css.

Please review.

Thanks,
Surinder Kumar