cubicweb #17258007 replace database.py by SQLAlchemy driver [rejected]

This is a suggestion by Denis.

database.py code isn't really great and we could benefit from using a well known, mature and maintained library instead (and that would be an occasion to contribute to it)

priorityimportant
typeenhancement
done in<not specified>
load0.000
load left0.000
closed by<not specified>