Feature: Support private key authentication in the Snowflake provider

[julesmga]

Describe the bug
The snowflake provider only supports password authentication, however a snowflake service account can't be assigned a password, only a public rsa key. Currently we have to set up a regular user for DataHub.

To Reproduce
Steps to reproduce the behavior:

1. Add a Snowflake source
2. See only password as authentication mechanism

Expected behavior
It would be nice to be able to use service accounts via a private key instead of a regular user with a password.

Screenshots
N/A

Desktop (please complete the following information):

• OS: Arch Linux
• Browser: Firefox
• Version: 133.0.3

Additional context
N/A