When reading, create the local equivalent of a dataclass, so that access
doesn't require ["foo"] key syntax.
Also implement the copy protocol, so that we can safely make clones of
the references returned by the ListModel.
As discussed on Reddit, the magic import logic is not very tool friendly and a little too magic perhaps. Instead, this patch introduces an automatic loader (`slint.loader`), which can traverse `sys.path` and lazily load `.slint` files by attribute lookup.
Closes#4856
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"
This provides a Model base class in Python and sub-classes of that
can be set as data models in slint.
The ListModel is provided as basic sub-class operating on a list() and
allowing mutation and notifying the view on the Slint side.
Similarly, an array declared in Slint is exposed as an object to Python
that looks like a Model.
Both support the sequence protocol.
Fixes#4135
