[Feature Request] Chunk borders for chunklocked accounts

[Anderzenn]

Is your feature request related to a problem? Please describe.
As a chunklocked account, we use a modified version of the normal GPU plugin from the region-locker plugin that shades the locked chunks darker than all other chunks, making it clear where your border is. But this is of course not possible with 117HD since the shading part of region locker is part of the GPU plugin.

Describe the solution you'd like
It would be awesome to have locked chunks shading as a part of 117, where it looks into region-locker's "unlocked chunks" and darkens or something the locked chunks.

Describe alternatives you've considered
Using 117HD, but with chunk border lines enabled. Chunk border lines however draw a line around every single chunk, and not just along the edge of your unlocked chunks

Additional context
Region Locker Github for reference :)