feat: Add config sections in-code

[John-Paul-R]

[John-Paul-R]

need to fix /essentialcommands config display and /essentialcommands config display <name> -- nontrivial, since logic needs to be added for 1) displaying sub-objects (config sections) and 2) retrieving config options by a path, instead of name (since there may be duplicate individual names now (e.g. the planned per-world RTP settings))