Remove extraneous semicolon

Fix runtime when build with -fsanitize=cfi

fix compiling errors on AIX

:(

- Uncommenting SPDLOG_FUNCTION will make MSVC fail to compile:
    __PRETTY_FUNCTION__ is shown in intellisense but it's not available at compile time
    https://stackoverflow.com/questions/48857887/pretty-function-in-visual-c

Avoid c-style casting

Support C++20 std::format as an alternative to fmtlib

Add std::tm formatter, fix spdlog::stopwatch formatter, conditionally use fmt::runtime in test_errors