Add a sub command to antctl to restore the original antrea-gw0 TX checksum state on all Nodes

[hongliangl]

Describe the problem/challenge you have

When #6843 is merged, the TX checksum on antrea-gw0 will be disabled on every K8s Node if the disableTXChecksumOffload option is set to true, potentially degrading performance. Antrea cannot restore the original TX checksum state of antrea-gw0 even if disableTXChecksumOffload is later set to false, as it does not store the original state. To restore the default TX checksum state, it is recommended to delete and recreate antrea-gw0 on each K8s Node, which can be a repetitive task.

Describe the solution you'd like

According to the discussion #6843 (comment), add a sub command to antctl to restore the original antrea-gw0 TX checksum state on all Nodes.

Anything else you would like to add?