Merge bitcoin/bitcoin#34017: fuzz: Add a test case for ParseByteUnits()

57b888c fuzz: Add a test case for `ParseByteUnits()` (Chandra Pratap)

Pull request description:

  `ParseByteUnits()` is the only parsing function in `strencodings.cpp` lacking a fuzz test. Add a test case to check the function against arbitrary strings and randomized `default_multiplier`.

ACKs for top commit:
  maflcko:
    lgtm ACK 57b888c
  dergoegge:
    utACK 57b888c
  marcofleon:
    crACK 57b888c

Tree-SHA512: c16557442987437e5e0c9d9a8b016df93e513e34acb78242a1f73dabc4482632ec57eb35cb4c84f9a1ea838fa6bda2094f2a8b52ace431f8064a79fad96e9a52

Author: fanquake

src/test/fuzz/string.cpp

@@ -147,4 +147,19 @@ FUZZ_TARGET(string)
         const bilingual_str bs2{random_string_2, random_string_1};
         (void)(bs1 + bs2);
     }
+    {
+        const ByteUnit all_units[] = {
+            ByteUnit::NOOP,
+            ByteUnit::k,
+            ByteUnit::K,
+            ByteUnit::m,
+            ByteUnit::M,
+            ByteUnit::g,
+            ByteUnit::G,
+            ByteUnit::t,
+            ByteUnit::T
+        };
+        ByteUnit default_multiplier = fuzzed_data_provider.PickValueInArray(all_units);
+        (void)ParseByteUnits(random_string_1, default_multiplier);
+    }
 }