Add CSS to format product control page

Page style is modified based on one of the templates from CoffCup. Page
layout, color and font are adjusted to fit the product control theme.
Format page style

Update CSS format to show CreateNew and SearchProducts in different
pages.

Adjustments are also made to improve the presentation of the
information:
- change the body background color to white
- set minimun height and bottom padding for main section
- adjust style for the suggestion box to distinguish it from the
backgound information
- use image to replace the Delete label