Changed the function append_range_all_keyparts to use sel_arg_range_seq_init / sel_arg_range_seq_next to produce ranges.
Also adjusted to print format for the ranges, now the ranges are printed as:
    (keypart1_min, keypart2_min,..)  OP (keypart1_name,keypart2_name, ..) OP (keypart1_max,keypart2_max, ..)

Also added more tests for range and index merge access for optimizer trace