Add support for postgres

[trey-ivy]

adds support for using a postgres backend.

set datasource-driver to pgx and pass the connection string in the datasource-url and you're all set

example usage in launch.json file for local debugging:

{
    
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Backend Debug",
            "type": "go",
            "request": "launch",
            "mode": "debug",
            "program": "/home/trey/src/bb-portal/cmd/bb_portal/main.go",
            "cwd": "/home/trey/src/bb-portal/",
            "env": {
                "GRPC_GO_LOG_VERBOSITY_LEVEL": "99",
                "GRPC_GO_LOG_SEVERITY_LEVEL": "info",
            },
            "args": [
                "--config-file=/home/trey/src/bb-portal/config/portal.jsonnet",
                "--bep-folder=/data/bep-files",
                "--datasource-driver=pgx",
                "--datasource-url=postgresql://postgres_user:postgres_password@localhost:5432/bbportal",
                "--blob-archive-folder=/data/blob-archive",
            ]
        },
        {
            "name": "Frontend Debug",
            "type": "node",
            "request": "launch",
            "cwd": "/home/trey/src/bb-portal/frontend",
            "runtimeExecutable": "npm",
            "runtimeArgs": [
                "run",
                "dev"
            ],
        },
    ],
    "compounds": [
        {
            "name": "bb-portal debug(frontend/backend)",
            "configurations": [
                "Backend Debug",
                "Frontend Debug"
            ],
            "stopAll": true
        }
    ]
}