serialize sqlite pages

[milahu]

learn about SQLite file format then generate the pages and write to disk directly.

now that kaitai has serialization
we can use it to write sqlite pages

this is an early draft...
it only works to write the database header, no pages
further progress requires serializing pages
and writing them to the correct byte offsets in the database file

use case: convert a 5 GB jsonl file to sqlite
torrents_byteoffsets_parse_jsonl_zst.py
with my script i reach only 5 MiB/s
the bottleneck are the sqlite insert queries
my system (under load) can read and decompress at 20 MiB/s