Fix EZP-23712: The content edit form moves if you put the mouse over the title

Also rewrote how the tech infos are shown/hidden to use only CSS and avoid
asynchronous tests because of a graphical effect
Removed the bottom padding on the header in the content edit page
Refactored the relation and relationlist field views to not duplicate code
Fixed a wrong comment in the relation field view
Fixed a minor cs issue in relationlist view test
EZP-23718: added a plugin to load an image variation
EZP-23718: added the image field view
EZP-23718: added a custom image alias to display images in the rawcontentview
Merge pull request #129 from ezsystems/ezp-23718_view_image

 EZP-23718: As an editor, I want to see the content of the Image fields in the PlatformUI
EZP-23432: Content creation by picking a content type
EZP-23432: added the content type group model
EZP-23432: Added a loadContentTypes method in the content type group model
EZP-23432: Updated the content create plugin to use the content type group model
EZP-23432: cleaned up and added tests for the content create plugin
EZP-23432: Moved the draft handling a dedicated plugins
Changed the REST model to use the document property of the Response object
Removed useless parse implementation in the content type model
Changed the default value of the fieldDefinitions attribute of type model
Make sure to parse the id of content in the corresponding model
EZP-23432: Implemented the content creation in the content model