Alternator TLS Authentication client counterpart

[dkropachev]

Jira task: https://scylladb.atlassian.net/browse/DRIVER-545
Jira epic: https://scylladb.atlassian.net/browse/DRIVER-40

Copied from Jira epic DRIVER-40:

Alternator is going to get certificate authentication: scylladb/scylladb#23684

We need to update clients to make it easy for user to feed client certificate to DynamoDB client.

Optionally:

1. Certificate to be reloadable.
2. Disable signature generation code by AWS SDK

Migrated from GitHub issue: scylladb/alternator-load-balancing#111