parser for dsn

fork from https://github.com/fonini/dsn-parser

``typescript
const DSNParser = require('dsn-parser');

const dsn = new DSNParser('pgsql://user:pass@127.0.0.1:5432/my_db?sslmode=verify-full&application_name=myapp');
dsn.getParts();

/*
{
driver: 'pgsql',
user: 'user',
password: 'pass',
host: '127.0.0.1',
port: 5432,
database: 'my_db',
params: { sslmode: 'verify-full', application_name: 'myapp' }
} */
``