Merge #13815: util: Add [[nodiscard]] to all {Decode,Parse}[...](...) functions returning bool

9cc0230cfc Add NODISCARD to all {Decode,Parse}[...](...) functions returning bool. Sort includes. (practicalswift)
579497e77a tests: Explicitly ignore the return value of DecodeBase58(...) (practicalswift)
145fe95ec7 tests: Check return value of ParseParameters(...) (practicalswift)
7c5bc2a523 miner: Default to DEFAULT_BLOCK_MIN_TX_FEE if unable to parse -blockmintxfee (practicalswift)

Pull request description:

  Changes in this PR:
  * ~~Add linter to make sure the return value of `Parse[...](...)` is checked~~
  * Add `__attribute__((warn_unused_result))` to all `{Decode,Parse}[...](...)` functions returning `bool`
  * Fix violations

  Context:
  * #13712: `wallet: Fix non-determinism in ParseHDKeypath(...). Avoid using an uninitialized variable in path calculation.` would have been prevented by this

Tree-SHA512: 41a97899f2d5a26584235fa02b1ebfb4faacd81ea97e927022955a658fa7e15d07a1443b4b7635151a43259a1adf8f2f4de3c1c75d7b5f09f0d5496463a1dae6

src/script/descriptor.cpp

@@ -478,7 +478,7 @@ std::vector<Span<const char>> Split(const Span<const char>& sp, char sep)
 }
 
 /** Parse a key path, being passed a split list of elements (the first element is ignored). */
-bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath& out)
+NODISCARD bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath& out)
 {
     for (size_t i = 1; i < split.size(); ++i) {
         Span<const char> elem = split[i];