partition_data_manager: Make data arrays constexpr

Previously the constructor for all of these would run at program
startup, consuming time before the application can enter main().

This is also particularly dangerous, given the logging system wouldn't
have been initialized properly yet, yet the program would use the logs
to signify an error.

To rectify this, we can replace the literals with constexpr functions
that perform the conversion at compile-time, completely eliminating the
runtime cost of initializing these arrays.