Signal & Receiver Interfaces

- An hour and a half yesterday night + some other unknown amount of hours some day last week
- Made a Streetlight BP, because I wanted to start making a number of "blockout prefabs" to better dress the LD as placeholders for proper assets (better visualize the intended context of the environment). In addition to THIS specifically being a test to turn something on and off with the Switch BP.
- Added Signal and Receiver interfaces to attach to any BP objects like the Switch and Streetlight objects. So I can systemically link them and then be able to modularly assign them as a level designer. This along with my "Interactable" interface being usable with the item selection system, will fill the LD with more LD object-based interactivity possibilities.