[BUG] - `%f` format string does not work in `StrPrint` and friends

[Jamesbarford]

Describe the bug
Using the %f formatting to format a float in a printf like function in HolyC does not work

Example Program

U0 Main()
{
  F64 f = 65.3;
  U8 *str = StrPrint(,"%f",f); // This line explodes
  "%s\n",str;                  // Should print: 65.3
  Free(str);
}

Expected behavior
The %f formatting should convert the float to a string without using something like C's snprintf(...). But possibly be ported out of TempleOS StrPrint.HC or another custom implementation written.

The function that we need to modifiy is ./src/holyc-lib/strings.HC