Merge #10581: Simplify return values of GetCoin/HaveCoin(InCache)

Summary:
21180ff Simplify return values of GetCoin/HaveCoin(InCache) (Pieter Wuille)

Tree-SHA512: eae0aa64fa1308191100cdc7cdc790c825f33b066c200a18b5895d7d5806cee1cc4caba1766ef3379a7cf93dde4bbae2bc9be92947935f5741f5c126d3ee991b

Backport of Core PR10581
https://github.com/bitcoin/bitcoin/pull/10581

Test Plan:

make check
test_runner.py

Reviewers: deadalnix, Fabien, jasonbcox, markblundeberg, O1 Bitcoin ABC, #bitcoin_abc

Reviewed By: deadalnix, O1 Bitcoin ABC, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D3620