Add support for '--config=clang-tidy' (#3559)

This sets things up to use `bazel` to run `clang-tidy` using
https://github.com/erenon/bazel_clang_tidy.

I'm fixing issues outside of explorer, and disabling clang-tidy for
targets in explorer that have legacy issues. I was going to disable
clang-tidy for targets in explorer such as interpreter anyways, because
they're slow to parse, and just extended that to the currently failing
targets.

toolchain/parse/extract.cpp

@@ -51,7 +51,7 @@ struct Extractable<NodeId> {
     if (trace) {
       *trace << "NodeId: " << tree->node_kind(*it) << " consumed\n";
     }
-    return NodeId(*it++);
+    return *it++;
   }
 };
 
@@ -288,7 +288,7 @@ struct Extractable {
     return ExtractTupleLikeType<T>(
         tree, it, end, trace,
         std::make_index_sequence<std::tuple_size_v<TupleType>>(),
-        (TupleType*)nullptr);
+        static_cast<TupleType*>(nullptr));
   }
 
   static auto Extract(const Tree* tree, Tree::SiblingIterator& it,