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/versionbits.cpp

@@ -199,7 +199,7 @@ FUZZ_TARGET_INIT(versionbits, initialize)
     const uint32_t signalling_mask = fuzzed_data_provider.ConsumeIntegral<uint32_t>();
 
     // mine prior periods
-    while (fuzzed_data_provider.remaining_bytes() > 0) {
+    while (fuzzed_data_provider.remaining_bytes() > 0) { // early exit; no need for LIMITED_WHILE
         // all blocks in these periods either do or don't signal
         bool signal = fuzzed_data_provider.ConsumeBool();
         for (int b = 0; b < period; ++b) {