Allow Lily ignore the error during walk job and continue with the walk.

[Terryhung]

Description

Currently, if Lily encounters an error in height during walk job, the job will be terminated. When we submit a large walk range, it becomes troublesome to have the job terminated midway.

Therefore, it is necessary to add an argument to the walk job that allows Lily to ignore the error and continue with the job.

Acceptance criteria

Lily has the capability to complete the walk job even if an error occurs.

Where to begin

https://github.com/filecoin-project/lily/blob/master/chain/walk/walker.go#L103