Tune concatenated operation instanciation, reference CR2005 geoid for Czechia and add (disabled by default) records for Czechia S-JTSK/05 based transformations

[rouault]

• ConcatenatedOperation::fixStepsDirection(): invert first and last steps when needed
• Database: add transformations_czechia.sql with CR2005 geoid for ETRS89 to Baltic 1957 height
• Database: add transformations_czechia_extra.sql for transformations based on S-JTSK/05
  For now this file is not integrated in the default build, due to
  licensing of grid cz_cuzk_table_yx_3_v1710_east_north.tif being not clarified (work in progress with CUZK).
  Thoat grid can be generated with the script https://github.com/OSGeo/PROJ-data/blob/master/cz_cuzk/convert_table_yx_3_v1710.py

Assuming the grids have been generated and are in the current directory,

$ cp data/proj.db $PWD && cat ../data/sql/transformations_czechia_extra.sql   | sqlite3 proj.db   # Add customizations_czechia.sql to proj.db
$ echo 50 15 100  |  PROJ_DATA=$PWD bin/cs2cs -d 3 "ETRS89" "S-JTSK / Krovak East North + Baltic 1957 height" --3d
-703011.900	-1058147.294 55.562