chore: Refactor string span management

[dranikpg]

Pulls iterator support from helio into the dragonfly repo. Also removes big chunk of #3154

[BorysTheDev]

Could you prevent to use it with rvalue

[dranikpg]

Added a delete

[BorysTheDev]

I think a better approach define move and copy constructors separately and you don't need this enable_if in this case

[dranikpg]

Yep, seems simpler

[kostasrim]

Suggested change

	inline std::string_view ToSV(const std::string& slice) {
	return slice;
	}
	inline std::string_view ToSV(std::string&& slice) = delete;
	constexpr auto kToSV = [](auto&& v) { return ToSV(v); };
	inline std::string_view ToSV(const std::string& slice) {
	return slice;
	}
	inline std::string_view ToSV(std::string&& slice) = delete;
	constexpr auto kToSV = [](auto&& v) { return ToSV(std::forward<decltype(v)>(v)); };

[kostasrim]

Th expression ToSV(v) treats v as an lvalue

[dranikpg]

True, missed that one 🤓