Combine const/enum with type error messages

[Sam-61s]

Fixes #164

When validation fails with both type and const/enum keywords, this PR shows only the more specific const/enum error with type-aware value filtering.

Changes:

• Enhanced constEnum handler to filter allowed values by type constraints
• Modified type handler to suppress errors when const/enum is present

[jdesrosiers]

It didn't occur to be that you'd have to duplicate the logic for determining the type in the constEnum handler. That tells me that my original thought that this should be one combined typeConstEnum handler is probably better.

[Sam-61s]

It didn't occur to be that you'd have to duplicate the logic for determining the type in the constEnum handler. That tells me that my original thought that this should be one combined typeConstEnum handler is probably better.

Now, I've combined the handlers into a single typeConstEnum handler with a shared resolveTypes() helper function to eliminate the duplicated type-resolution logic.

[jdesrosiers]

This looks way more complicated than it should be. Can you see if it can be simplified? Also, I'd like to see a few more tests. This is a complicated feature especially when it comes to schema locations. Let's see if we can cover some more edge cases.

[jdesrosiers]

The added tests look good. I left a suggestion to try to help simplify the filtering approach.

[jdesrosiers]

If we do the filtering as we go, we can skip that whole large block of code dedicated to filtering. I think this code is more clear and concise than filtering after.

Suggested change

	const keyword = await getSchema(schemaLocation);
	const keywordJson = new Set([jsonStringify(/** @type Json */ (Schema.value(keyword)))]);
	allowedJson = allowedJson?.intersection(keywordJson) ?? keywordJson;
	const keyword = await getSchema(schemaLocation);
	const keywordJson = new Set();
	if (allowedTypes.has(Schema.typeOf(keyword))) {
	keywordJson.add(jsonStringify(Schema.value(keyword)));
	}

[Sam-61s]

I refactored the const/enum collection to filter by type inline, as suggested.

[jdesrosiers]

Yeah, that looks much better. I left a few more note for things that could be improved.

[Sam-61s]

cleanup improvement done..

1. removed duplicate integer cleanup
2. used Schema.iter & Schema.typeOf for enum
3. removed unnecessary early return
4. consolidate all returns at the end