This adds an icon that is displayed to the left of the title, and is
also shown for Menus are inside of a parent menu.
Closes#7791
ChangeLog: Added icon property to MenuItem and Menu
By default it's enabled, of course. This property is not only added to
MenuItem, but Menu as well - since they can be nested. It's also
possible to select a disabled item, but it's hard to modify that since
it's logic is written in Slint. You should be prevented from activating
it with a tap or key press at least.
See #7791
The struct held provides access to the design metrics of the font scaled
to the font pixel size used by the element.
ChangeLog: Slint Language: Added font-metrics property to `Text` and `TextInput`.
Closes#6047
Updated the version from 1.1 to 1.2
Renamed the header to "Slint Royalty-free Desktop, Mobile, and Web Applications License"
Added definition of "Mobile Application" and grant of right
Moved "Limitations" to 3rd section and "License Conditions - Attributions" to 2nd section
Added flexibility to choose between showing "MadeWithSlint" as a dialog/splash screen or on a public webpage
Moved the para on copyright notices to section under "Limitations"
