[Testbuild] Add support for flares/lighting

• Fix mentioned issue.

Ping me here or on discord if you would like any assistance!

PoC finished with commit: 2b647ce

Open TODOs

Signals

• Move rotation, offset and pitch to contentpack-entry and remove it from obj-group
• Add ability to state multiple obj-groups / remove need for "lightflare"-group
• Implement always-on
• Add caching
• Add preloading
• Add support for blocks modified with the manipulator tool (Difficulty: Severely depressing)

Complex signals

• Implement flares
• Add caching
• Add preloading

Signs

• Implement flares
• Add caching
• Add preloading

Assets

• Implement flares
• Add caching
• Add preloading

Levers

• Implement flares
• Add caching
• Add preloading

Others

• Create documentation
• Provide test build in discord and wait for responses
• Create release 1.4.0