Use DBArray for all LDB, LMT, and LMU structs

[mateofio]

Depends on #379

This PR adds C++20 compatible lcf::Span and a new DBArray array class, which has a similar storage policy and small memory footprint like DBString. It also adds a DBBitArray bit vector replacement for vector<bool>.

This is a WIP, a lot of refactoring is needed in liblcf to get this new Array type working for all the chunks.

Here are some initial numbers where we just convert EventCommand::parameters to use DBArray

Game	Ldb Size	std::string + std::vector	DBString + std::vector	DBString + DBArray
HH3	16MB	135.7MB	94.7MB	68.7 MB
Heroes Realm	27MB	301.6MB	204.3MB	143.3 MB
Violated Heroine	11MB	75.9MB	54.6MB	41.4 MB
Yume 2kki	1.4MB	8.0MB	6.0MB	4.9 MB