Locked object can be deleted on one extra epoch away from lock expiration

[abereziny]

Let say we have:

1. Current epoch is 100
2. Object is put to the container
3. Object is locked with lock with expiration at epoch 101

Steps:

1. Tick epoch, current epoch becomes 101
2. Try to delete object

Expected Behavior

Object should be removed since lock expired at current epoch

Current Behavior

Object cannot be removed and treated as locked object until next extra epoch is ticked

Tests

• pytest_tests/testsuites/object/test_object_lock.py#test_after_lock_expiration_with_expire_at_user_should_be_able_to_delete_object
• pytest_tests/testsuites/object/test_object_lock.py#test_after_lock_expiration_with_lifetime_user_should_be_able_to_delete_object

[acid-ant]

Blocked by:

• Make it clear that EXPIRATION_EPOCH is the last "available" epoch for all entities neofs-api#253
• EXPIRATION_EPOCH must be the last "available" epoch for all entities neofs-sdk-go#370

[acid-ant]

@abereziny it works as expected. Fixed help message for parameter here #2169. I've added one extra epoch tick and test passed.