* refactor: make this variable const
* refactor: replace redundant type with auto
* refactor: use the nullptr literal
* refactor: replace declaration by structured binding declaration
* chore: fix shadowed variable warning
"byte" is declared by a third-party UTP header
* refactor: tr_variantFromFile, tr_variantToFile take a string_view filename
* refactor: include <memory> when using shared_ptr or unique_ptr
* refactor: include <cstdio> iff we use it
* refactor: include <cstring> iff we use it
* refactor: include <cstdlib> iff we use it
* refactor: include <string_view> or <string> iff we use it
* refactor: include <array> iff we use it
* refactor: include <ctime> iff we use it
* refactor: include <cctype> iff we use it
* refactor: misc #include cleanups in libtransmission
