Add TestCanvas project.

Restore https://github.com/touchvg/vgios-demo/tree/53eee8956be461afb6ff3c2ba11e69e5e7982b48
https://github.com/touchvg/vgios-demo/tree/53eee8956be461afb6ff3c2ba11e69e5e7982b48/ios/tests/TestCanvas
Test dummy view.