feat: Allow feast snowflake to read in byte string for private-key authentication

[arturkolakowski]

What this PR does / why we need it:

Allows the user to pass private_key as a byte string for Snowflake key-pair authentication rather than only limiting the ability to refer to the file path where the private key is stored.
Gives the ability to pass in private_key from a Secret Manager service (i.e: Google Cloud Secret Manager)

Which issue(s) this PR fixes:

Fixes

[tokoko]

just curious, are you able to set bytes value from yaml as well or will this only work in python?

[arturkolakowski]

just curious, are you able to set bytes value from yaml as well or will this only work in python?

yes it will work, for example, feature_store.yaml can include private_key of format

'-----BEGIN ENCRYPTED PRIVATE KEY-----
.
.
-----END ENCRYPTED PRIVATE KEY-----'

[tokoko]

Wouldn't that be interpreted as a string and therefore as a file path?

[arturkolakowski]

As I am looking through the code base and considering this example: SnowflakeOfflineStore
SnowflakeOfflineStore establishes a snowflake connection with GetSnowflakeConnection (/feast/infra/utils/snowflake/snowflake_utils.py)

with GetSnowflakeConnection(config.offline_store) as conn:
            snowflake_conn = conn

when parse_private_key_path gets called private_key is already of type bytes so this way only works in python, my apologies.

[tokoko]

@arturkolakowski how about we add another field in config instead (something like private_key_content) which would simply take precedence?

[arturkolakowski]

@tokoko Made changes based on the request

[tokoko]

lgtm, thanks