Add region visibility filters

[haykam821]

This pull request adds region visibility filters, which aim to solve the problem of overlapping regions not being easily distinguishable.

Region visibility filters can be given with a command such as the following:

give @s nucleoid_creator_tools:region_visibility_filter{Region: ["a", "b"]}

Region visibility filters use the particle outline color of their first region. Their tooltip lists all regions.

Using a region visibility filter will immediately apply it to the current editor. Editors can also clear their current filter by sneaking while using a region visibility filter.

While out of scope and potentially difficult for this initial implementation, a few improvements could be made:

• Blend all region colors together rather than take the first region's color
• Allow using commands to accomplish the same functionality
• Allow using wildcards for regions, such as *_spawn to match red_spawn and blue_spawn

Fixes #8