Implicit weights are now handled according to the Unicode version
(14.0.0 vs earlier versions).

- Adding a new member MY_UCA_INFO::version

- Copy logical positions and the version from "src_uca" to "new_uca"
  in init_weight_level().

- Adding a "const MY_UCA_INFO *" parameter to a few functions
  to know Unicode version to generate implicit weights accordingly:
  - during the collation initialization time, to pages which are
    a mixture of explicit and implicit weights
  - during comparison time, for fully implicit pages