Fix generating properties that start with an uppercase letter

Summary: We were not adjusting the property name to the getter letter-casing.

Test Plan: See added test, also fixes the issue that made me realize this issue.

Reviewers: Frameworks, davidedmundson

Reviewed By: davidedmundson

Subscribers: ngraham, aacid, kde-frameworks-devel

Tags: Frameworks

Differential Revision: https://phabricator.kde.org/D24010