[schema2sql] Avoid "parsing" SQL statements for database initialization
A big SQL string was generated, then splitted. This caused bug if some value in
the schema (eg vocabulary, default) contained the separator (';').
To properly fix this, yield each individual statement instead of generating a
string.
Closes #14050899
version=3
opts=uversionmangle=s/(rc|a|b|c)/~$1/ \
https://pypi.debian.net/cubicweb/cubicweb-(.+)\.(?:zip|tgz|tbz|txz|(?:tar\.(?:gz|bz2|xz)))