doesDbExist method
Implementation
bool doesDbExist() {
_setPassword();
/// lists the database.
final sql =
"psql --host=${_dbSettings.host} --port=${_dbSettings.port} -t -q -c '\\l ${_dbSettings.dbName};' -U postgres";
final results = sql.toList(skipLines: 1);
return results.isNotEmpty &&
results.first.contains('${_dbSettings.dbName}');
}