Rename Lisk internal getProperties() methods to avoid collisions

Summary:
See some discussion here:

https://github.com/phacility/phabricator/commit/24a6eeb8d8a52b592e456d110934670d4ace9b31#commitcomment-7334892

The `protected $properties;` storage parameter added to `ProjectColumn` is shadowed by `getProperties()` in the base class.

Although this works correctly for me, it's ambiguous and worth fixing. Make the base class methods explicit.

Test Plan: Used `grep` to find callers for both methods and renamed them.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D10210