Support macCatalyst

[freakboy3742]

What is the problem or limitation you are having?

Adding builds for macCatalyst is necessary to support beeware/Python-Apple-support#117

Describe the solution you'd like

Patches and configuration changes to produce macCatalyst binaries are part of a standard build

Describe alternatives you've considered

Strictly, this might not actually be required, as standard macOS binaries might be usable; however, binaries that have been clearly built with macCatalyst in mind will ensure that there's no ABI issues.

Additional context

No response