This is commit 1/3 to address smartnode-issue-572. This commit includes changes to:
1) add an enable-partial-rebuild flag to the rebuild flow, 2) return error data per key from the API and 3) add logging to inform the user of the outcomes.

Update recover-keys.go

Update go.mod

… support test and partial recovery modes.

This change addresses all comments from the first draft of the PR to introduce partial recovery support. This removes multiple implementations of a KeyRecoveryManager interface and instead uses class fields to determine how to appropriately enact the recover code flow.