Decide if the form title should be mandatory

[garethbowen]

In web-forms the form will fail to load if it doesn't have a <h:title> element.

web-forms/packages/scenario/test/label-hint-text.test.ts

Lines 32 to 34 in 6015ab6

	* - Fails as directly ported, as we presently expect a form definition to
	* explicitly include a `<h:title>`. An alternate parameterization of the
	* test includes a title so that the rest of the test may proceed.

This isn't a requirement in other implementations so either; decide whether it's something we still want to enforce and document the difference, or allow it and fix the code to handle it gracefully.