registry/expire: Should not use tokens expiration time

[denis-tingaikin]

Expected Behavior

registry/expire: Should not look at the token expiration time

Current Behavior

registry/expire: Should looks at the token expiration time on selecting expiration time for the endpoint.

Failure Information (for bugs)

Steps to Reproduce

1. Create a registry/expire chain element.
2. Do a request with a chain of tokens (t1, t2, t3, t4).
3. Set the path index on 3.
4. Make the t1 token expiration time lower in the chain.

Actual: expire will use the t4 token expiration time when t1 is lower. Expected: expire should not look at tokens expiration time. The logic should be moved to the registry/refresh client.

Context

https://github.com/networkservicemesh/sdk/tree/main/pkg/registry/common/expire