add postgresql metadata support and force utf8 encode on non-utf8 locale

[clojurians-org]

add support for postgresql metadata and enforce utf8 encode on various machine.

it seesm mysql run on non-utf8 locale will lead to chinese messy character to display.
some chinese friend report it to me even in docker setup.

so i force the utf8 in my script.
anyway, i can enforce utf8 for database using the following statement for database setup and gms ebean connection.

echo "CREATE DATABASE datahub default character set utf8" | mysql -u root -S /nix/var/run/mysqld.sock

export EBEAN_DATASOURCE_URL="jdbc:mysql://localhost:3306/datahub?useSSL=false&useUnicode=yes&characterEncoding=UTF-8"

[mars-lan]

Thanks for the contribution!