[meta] Why network addresses in meta are String typed

[ClSlaid]

I'm interested in your hummock engine. After taking a brief look into the code of meta I found most of the network addresses are String typed.
Typing network addresses with std::net::SocketAddr could represent them as 16-bytes-sized enums and 2-bytes-sized port numbers in memory, saving space and time on heap allocations or deallocations. And comparing between addresses could be faster since much fewer reads are required.