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/scriptnum_ops.cpp

@@ -28,7 +28,7 @@ FUZZ_TARGET(scriptnum_ops)
 {
     FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
     CScriptNum script_num = ConsumeScriptNum(fuzzed_data_provider);
-    while (fuzzed_data_provider.remaining_bytes() > 0) {
+    LIMITED_WHILE(fuzzed_data_provider.remaining_bytes() > 0, 1000000) {
         CallOneOf(
             fuzzed_data_provider,
             [&] {