DNN-6199  Html Module UX Optimization

Things to improve :
- You need always to scroll to find the save button
- you have sometimes 2 vertical scrollbars (editor + popup)
- you have secondary information which disturb the main functionality

Solutions :
- put the buttons in a fixed part at the bottom
- never show the scollbars of the popup (auto resize of the editor - Responsive Editor in popups )
- hide publish information for "Direct publish"
- replace preview and version history sections with a "render mode" = Edit | preview | version history (buttons)
- put the Basic / rich text bow radios button in on the button line as combox

Implementations details :
- the auto resize is implemented for RadEditor, CKEditor and Basic Text box (implemented by javascript hacks)
- the auto resize is only active in popups

(printscreen in attachment in dnntracker)