Handle Uris with no host and params (e.g 'airbnb://')

Not sure if it's a bug or on purpose but DeepLinkDispatch does not handle Uris with just the base scheme, like `airbnb://`. In that case, `DeepLinkUri.parse()` with return `ParseResult.INVALID_HOST`. Not sure if we should handle it, any other thoughts?

Start by reading the implementation of DeepLinkUri.parse() and how ParseResult.INVALID_HOST is handled. Review the existing discussion to determine whether a URI such as `airbnb://` should be accepted or rejected, then define regression coverage and the expected result once that behavior is decided.

Written by the indexing model from the issue text.