Below one will reinstall the two PHP modules and restore the /etc/php/7.0/mods-available folder:
sudo apt install --reinstall php7.0-json php7.0-sqlite3
And below one should enable the mods and create appropriate symlinks:
sudo phpenmod json sqlite3
After reinstalling and enabling, post outcome for all the commands from my first posting pls ?
EDIT: And post outcome for below one just to be sure ?
php -m
EDIT2: after enabling the two mods, you most always have to restart the web daemon to apply:
sudo service lighttpd restart