[lib] resend messages after session creation request

Summary:
ENG-6982.

The code here is executed in two cases:

1. First session request - this call is a no-op because we haven't sent any Outbound messages yet.
2. Session request with higher session - this means that the device that sent the request has a malformed session and we need to re-encrypt and resend all not confirmed messages.

Depends on D13032

Test Plan:

1. Create a session between devices A and B
2. On B comment out sending confirmation.
3. Send some messages from A to B
4. From B to A send session request with higher session counter.
5. Test that all messages are sent again and decrypted successfully

Reviewers: tomek

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D13056