feat(chdb): implement chdb - the embedded clickhouse - backend

[kszucs]

A big chunk of the backends testing suite is already passing, but there is still work to do:

1. Support passing in memory tables, this can be done using the same "pass as a file" trick used in chdb.dataframe
2. Better error handling
3. Pass the right dialect everywhere

Test suite is currently at 247 failed, 1067 passed, 28 skipped, 29854 deselected, 131 xfailed, 6 errors