fuzz: replace every fuzzer-controlled loop with a LIMITED_WHILE loop

Blindly chose a cap of 10000 iterations for every loop, except for
the two in script_ops.cpp and scriptnum_ops.cpp which appeared to
(sometimes) be deserializing individual bytes; capped those to one
million to ensure that sometimes we try working with massive scripts.

There was also one fuzzer-controlled loop in timedata.cpp which was
already capped, so I left that alone.

git grep 'while (fuzz' should now run clean except for timedata.cpp

src/test/fuzz/script_descriptor_cache.cpp

@@ -17,7 +17,7 @@ FUZZ_TARGET(script_descriptor_cache)
 {
     FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
     DescriptorCache descriptor_cache;
-    while (fuzzed_data_provider.ConsumeBool()) {
+    LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 10000) {
         const std::vector<uint8_t> code = fuzzed_data_provider.ConsumeBytes<uint8_t>(BIP32_EXTKEY_SIZE);
         if (code.size() == BIP32_EXTKEY_SIZE) {
             CExtPubKey xpub;