Implement GetID for DescriptorScriptPubKeyMan
Implement GetID for DescriptorScriptPubKeyMan

Summary: Backport of Core [[https://github.com/bitcoin/bitcoin/pull/16528 | PR16528]] [14/43] : https://github.com/bitcoin/bitcoin/pull/16528/commits/46c46aebb7943e1e2e96755e94dc6c197920bf75

Test Plan:
  ninja all check-all

Reviewers: #bitcoin_abc, majcosta

Reviewed By: #bitcoin_abc, majcosta

Differential Revision: https://reviews.bitcoinabc.org/D8412

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