Enable operator info in bpls

[eisenhauer]

Add --list_operators to bpls. This will list the operators necessary to read a particular file, even if the current version of bpls has not been built with those particular operators. (Maybe we need something else that lists what this version of bpls has been built with?)

(base) eisen@Endor build % bin/bpls --list_operators TestBPWriteReadZfpComplex
  char            bpChars       500*{1, 100}
  float complex   bpComplexes   500*{1, 100}
  double complex  bpDComplexes  500*{1, 100}
  double          bpDoubles     500*{1, 100}
  float           bpFloats      500*{1, 100}
  int32_t         bpInts        500*{1, 100}
  int16_t         bpShorts      500*{1, 100}
  uint8_t         bpUChars      500*{1, 100}
  uint32_t        bpUInts       500*{1, 100}
  uint16_t        bpUShorts     500*{1, 100}
Operators used in this file:
 * zfp
(base) eisen@Endor build % 

[eisenhauer]

Merging as failures unrelated.