BS: reduce interface state to active/revoked

[lukedirtwalker]

Contributes #2926

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This change is 

[oncilla]

Reviewed 9 of 9 files at r1.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @lukedirtwalker)

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go/beacon_srv/internal/ifstate/ifstate.go, line 160 at r1 (raw file):

// and propagation are reset to the zero value. The return value indicates,
// whether the state is expired or revoked when the call returns.
func (intf *Interface) Expire() bool {

The doc string needs to be updated.
Probably, the method should now be called Revoked or similar.

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go/beacon_srv/internal/ifstate/ifstate.go, line 179 at r1 (raw file):

// interface has been activated in the meantime and should not be revoked.
// This is indicated through an error.
func (intf *Interface) Revoke(rev *path_mgmt.SignedRevInfo) error {

Update doc string.
Should probably be called SetRevocation or similar

[lukedirtwalker]

Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @oncilla)

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go/beacon_srv/internal/ifstate/ifstate.go, line 160 at r1 (raw file):

Previously, Oncilla wrote…

The doc string needs to be updated.
Probably, the method should now be called Revoked or similar.

Done.

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go/beacon_srv/internal/ifstate/ifstate.go, line 179 at r1 (raw file):

Previously, Oncilla wrote…

Update doc string.
Should probably be called SetRevocation or similar

Done.

[oncilla]

Reviewed 6 of 6 files at r2.
Reviewable status: complete! all files reviewed, all discussions resolved

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doc/BeaconService.md, line 139 at r2 (raw file):

The BS periodically evicts beacons that contain revoked interfaces.

### Interfaces State

💯 for remembering to update

[oncilla]

Reviewable status: complete! all files reviewed, all discussions resolved

[oncilla]

Reviewed 1 of 1 files at r3.
Reviewable status: complete! all files reviewed, all discussions resolved