Prepare LibTIFF Tools Removal

I wonder which tools should continue to be provided as "unsupported" and which can be moved to the archive, as was done in 2016. I understood that only tiff2pdf and tiff2ps (apart of tiffinfo and tiffdump) are requested for further distributions.

Also, I would remove the "-i" option (ignore errors) in all tools in "unsupported".

List updated 24.07.23 to summarize discussion up to now.

tools/
  tiffinfo.c
  tiffdump.c
  tiffcp.c
  tiffset.c
  tiffsplit.c

tools/unsupported/
  tiff2pdf.c
  tiff2ps.c

archive/tools/
  fax2ps.c
  fax2tiff.c
  pal2rgb.c
  ppm2tiff.c
  raw2tiff.c
  rgb2ycbcr.c
  thumbnail.c
  tiff2bw.c
  tiff2rgba.c
  tiffcmp.c
  tiffcrop.c
  tiffdither.c
  tiffgt.c
  tiffmedian.c

• The tools documentation will be moved to archive/doc/tools.

• All tests related to moved tools (e.g tiffcrop-xx.sh) will also be moved to archive/test and test scripts (test/CMakeLists.txt and test/Makefile.am) adapted.

• tiffcp.c will be used to have the possibility for tests with codecs. Some tests will be added.

• Version set to 4.6.0 but SO version can stay.

• For CMake the option “tiff-tools-unsupported” is added to compile the unsupported tools and install them in bin/unsupported.

• The same is done for Automake. (I would need help with this).