Fixes to handle JSON params, files clause in copy into, reserved words

[rad-pat]

Reserved words updated with output from select * from information_schema.keywords - is that correct? It might be good to have some automated process that updates this list when a new version of Databend is released.

I added the AVRO file format now it is handled by Databend

Allows use of JSON in parameters, and files clause was not working correctly in copy into, added fix and test for that.

[everpcpc]

INTERNALERROR>           ^^^^^^^^^^^^^^^^^^^^^^
INTERNALERROR>   File "/home/runner/work/databend-sqlalchemy/databend-sqlalchemy/databend_sqlalchemy/databend_dialect.py", line 1043
INTERNALERROR>     result += f" FILES = ({', '.join(["'{0}'".format(f) for f in copy_into.files])})"
INTERNALERROR>                                                                                      ^
INTERNALERROR> SyntaxError: f-string: unmatched '['

[rad-pat]

INTERNALERROR>           ^^^^^^^^^^^^^^^^^^^^^^
INTERNALERROR>   File "/home/runner/work/databend-sqlalchemy/databend-sqlalchemy/databend_sqlalchemy/databend_dialect.py", line 1043
INTERNALERROR>     result += f" FILES = ({', '.join(["'{0}'".format(f) for f in copy_into.files])})"
INTERNALERROR>                                                                                      ^
INTERNALERROR> SyntaxError: f-string: unmatched '['

Ah, python 3.12 vs lesser version issue. Will fix 👍