Rename parse_node -> node_id (#3760)

This was previously discussed at
https://discord.com/channels/655572317891461132/655578254970716160/1209975051588210729.
I'm initiating this mainly because we typically use "id" suffixes to
indicate an `IdBase` being passed around and the non-id suffix of
`parse_node` suggests at it carrying more data than it actually does.
There used to be more reason for avoiding `node_id` because
`SemIR::InstId` used to be named `NodeId`, but that's no longer
necessary. As a consequence, I'd like to rename `parse_node` to more
precisely reflect its type.

In full, this is doing:

```
parse_node_kind -> node_kind
parse_node -> node_id
ParseNodeCategory -> NodeCategory
ParseNodeKind -> NodeKind
ParseNode -> NodeId
```

This is primarily in check and sem_ir, but with some `parse_node_kind`
references in parse too.

Pluralization is consistent with name forms on both sides, so that
wasn't part of my replacements.

toolchain/parse/context.cpp

@@ -402,14 +402,13 @@ auto Context::ConsumeListToken(NodeKind comma_kind, Lex::TokenKind close_kind,
   }
 }
 
-auto Context::RecoverFromDeclError(StateStackEntry state,
-                                   NodeKind parse_node_kind,
+auto Context::RecoverFromDeclError(StateStackEntry state, NodeKind node_kind,
                                    bool skip_past_likely_end) -> void {
   auto token = state.token;
   if (skip_past_likely_end) {
     token = SkipPastLikelyEnd(token);
   }
-  AddNode(parse_node_kind, token, state.subtree_start,
+  AddNode(node_kind, token, state.subtree_start,
           /*has_error=*/true);
 }