1. Adding separate functions for different Unicode versions
  - my_uca_520_implicit_weight_primary()
   It calculates implicit weights according to the old algorithm
   that we used to dump Unicode-5.2.0 weights.

  - my_uca_1400_implicit_weight_primary()
    It calculates implicit weights according to
    https://unicode.org/reports/tr10/#Values_For_Base_Table
    as of November 2021, Unicode version 14.0.0.

2. Adding the "@version" line recognition when dumping allkeys.txt.
   Implicit weights are dumped according to @version.

3. Dumping the scanned version as a "#define"

4. Removing dumping MY_UCA_NPAGES, MY_UCA_NCHARS, MY_UCA_CMASK, MY_UCA_PSHIFT,
   as they are defined in ctype-uca.c. Removing dumping of "main()", it's not
   needed. The intent is to generate an *.h file which can be put directly
   to the MariaDB source tree.

5. Adding a structure MY_DUCET. It now contains weights for single
   characters and version related members. Later we'll add contractions
   and logical positions in here.