Reduction of the number of uses of the define BLF_DRAW_STR_DUMMY_MAX
by using actual sizes of static character arrays.

BLF_DRAW_STR_DUMMY_MAX (1024) is used 54 times as a maximum string length. But in half (27) of the uses the actual size of the character array is known and is less than this amount. The maximum argument is there for safety. Operations will stop when the terminating zero is hit or the maximum length is reached. But in these cases this maximum is beyond the allocated memory size so will cause buffer overflow if the string is not null-terminated.