Fixes#34541
Renamed MAX_DIGITS to MAX_DECIMALS, since it only changes the
amount of digits after the decimal point.
Increased MAX_DECIMALS to 32, and made String::num use
MAX_DECIMALS consistently. If -1 is passed as
decimal precision to String::num, it now gets changed to
the correct precision based on the number's magnitude,
instead of using printf default(which is 6)
String::num_real also calculates the correct precision now.
Also made the types used in floating-point math more
consistent in a few places.
09a905ca80