Gui 1213 Instance Types Update Page

https://eucalyptus.atlassian.net/browse/GUI-1213
Initially the page was based on the landing page template due to the presence for the table, but later realized that this page was rather, more similar to the detail page than landing page; notice that much of the landing page features are not used, such as filter, tile view, etc. So, there isn't much code to inherit from the landing page other than the 'getItems()', which also has been customized for this page.