pgsql: Additional unicode primitive functions.

Additional unicode primitive functions.

Introduce unicode_version(), icu_unicode_version(), and
unicode_assigned().

The latter requires introducing a new lookup table for the Unicode
General Category, which is generated along with the other Unicode
lookup tables.

Discussion: https://postgr.es/m/CA+TgmoYzYR-yhU6k1XFCADeyj=Oyz2PkVsa3iKv+keM8wp-F_A@mail.gmail.com
Reviewed-by: Peter Eisentraut

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a02b37fc083239a07f1ac02951d208235efb218b

Modified Files
--------------
doc/src/sgml/func.sgml | 109 +-
src/backend/utils/adt/varlena.c | 61 +
src/common/Makefile | 1 +
src/common/meson.build | 1 +
src/common/unicode/Makefile | 19 +-
src/common/unicode/category_test.c | 108 +
.../unicode/generate-unicode_category_table.pl | 204 +
src/common/unicode/generate-unicode_version.pl | 46 +
src/common/unicode/meson.build | 40 +
src/common/unicode/norm_test.c | 2 +-
src/common/unicode_category.c | 195 +
src/include/catalog/pg_proc.dat | 12 +
src/include/common/unicode_category.h | 68 +
src/include/common/unicode_category_table.h | 4040 ++++++++++++++++++++
src/include/common/unicode_version.h | 14 +
src/test/icu/t/010_database.pl | 4 +
src/test/regress/expected/unicode.out | 18 +
src/test/regress/sql/unicode.sql | 4 +
18 files changed, 4924 insertions(+), 22 deletions(-)