vt: move UCS tables to the "shipped" form

Use the "shipped" mechanism to copy pre-generated tables to the build
tree by default. If GENERATE_UCS_TABLES=1 then they are generated at
build time instead. If GENERATE_UCS_TABLES=2 then
gen_ucs_recompose_table.py is invoked with --full.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250417184849.475581-15-nico@fluxnic.net


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>