Release changes

• new feature: possibility to change the layout color
• new feature: zoom in/out, panning the previewed image
• handling desktop GUI correctly on MacOS, since GioUI should run on the main thread
• mouse select support for layout selection
• enable buttons to listen on click events
• enabled content scrolling
• enable fast navigation inside the editor modal by PgUP/Down
• embed sample content into the build file
• improved performance by using StringBuilder for content edit
• avoid generating diagrams from non UTF files
• prohibit saving non UTF content
• refactoring UI widgets
• fix: CRLF issue
• fix: close progress modal in case of an error
• fix: diagram progress modal
• fix: hide cursor from progress modal
• fix: help modal not showing up after other modals were activated
• fix: wrapping content line
• fix: premature autohide of the console log
• fix: wrapping console text
• fix: embed font file
• fix: use ESC key for closing opened modals
• fix: GUI window aspect ratio