Merge bitcoin/bitcoin#25734: wallet, refactor: #24584 follow-ups

8cd21bb279 refactor: improve readability for AttemptSelection (josibake)
f47ff71761 test: only run test for descriptor wallets (josibake)
0760ce0b9e test: add missing BOOST_ASSERT (josibake)
db09aec937 wallet: switch to new shuffle, erase, push_back (josibake)
b6b50b0f2b scripted-diff: Uppercase function names (josibake)
3f27a2adce refactor: add new helper methods (josibake)
f5649db9d5 refactor: add UNKNOWN OutputType (josibake)

Pull request description:

  This PR is to address follow-ups for #24584, specifically:

  * Remove redundant, hard-to-read code by adding a new `OutputType` and adding shuffle, erase, and push_back methods for `CoinsResult`
  * Add missing `BOOST_ASSERT` to unit test
  * Ensure functional test only runs if using descriptor wallets
  * Improve readability of `AttemptSelection` by removing triple-nested if statement

  Note for reviewers: commit `refactor: add new helper methods` should throw an "unused function warning"; the function is used in the next commit. Also, commit `wallet: switch to new shuffle, erase, push_back` will fail to compile, but this is fixed in the next commit with a scripted-diff. the commits are separate like this (code change then scripted-diff) to improve legibility.

ACKs for top commit:
  achow101:
    ACK 8cd21bb279
  aureleoules:
    ACK 8cd21bb279.
  LarryRuane:
    Concept, code review ACK 8cd21bb279
  furszy:
    utACK 8cd21bb2. Left a small, non-blocking, comment.

Tree-SHA512: a1bbc5962833e3df4f01a4895d8bd748cc4c608c3f296fd94e8afd8797b8d2e94e7bd44d598bd76fa5c9f5536864f396fcd097348fa0bb190a49a86b0917d60e

test/functional/wallet_avoid_mixing_output_types.py

@@ -124,6 +124,7 @@ class AddressInputTypeGrouping(BitcoinTestFramework):
 
     def skip_test_if_missing_module(self):
         self.skip_if_no_wallet()
+        self.skip_if_no_sqlite()
 
     def make_payment(self, A, B, v, addr_type):
         fee_rate = random.randint(1, 20)