ENH: functionObjects: refactor and extend histogram

• new submodels:

  • 'equalBinWidth': groups data into bins of equal widths (previous behaviour)
  • 'unequalBinWidth': groups data into bins of unequal widths

• output files per time-step are replaced with a single output file

• silently deprecates the input entries: 'setFormat' and 'formatOptions'

Meta-data

• EP1969
• linux64ClangDPInt32Opt (clang11)
• linux64GccDPInt32Opt
• linux64GccSPDPInt64Debug
• Alltest: No new error/No change in existing output