Stub version of expandable search dialog

Introduced the SearchDialog component, which is just a plain rect for now.
The SearchDialog apparition on the screen is animated with a
translation-opacity-scale effect with origin in top right corner, where the
Search button is positioned.

Added icons/background.png and icons/serach.png resources, which are self made
and will be probably replaced.
Some tweaks on SearchDialog
Implemented a list of (stub) expandable elements

As for now, the SearchDialog provides a stub list of elements which have random
height and which are foldable and expandable by clicking on their header.
Implemented exclusive element expansion

At most one element can be viewed (expanded) in the list of items in
SearchDialog. Opening another element while there's already one expanded will
close the previous, thus, elements are "mutually exclusive".
Added title bar with close button to SearchDialog

Dialog is now closeable again.
Restyled SearchDialog

Using BorderImage instead of a plain rectangle and added the close button which
matches the rest of theme.
Added text and image for elements in SearchDialog

Also, using provided resources as temporary replacement for ugly rectangles.
Text optimizations...
Added stub mechanism for requesting profile change
Graphical improvements related to SearchWindow

A better looking search button was added in main window, font and color changes
in SearchWindow, other light touches.