Add campaign check sync support

[andrewstillv15]

MATTER-86

Summary

• Add Check.Campaign via a new lightweight CampaignId type
• Return created checks from CopyChecksToCampaign, and add SourceCheck to campaign check nodes
• Add ChecksCopyToCampaignPayload.CreatedChecks (generated) and Check.SourceCheck (generated)
• Fix EnableOn being silently dropped when converting check inputs

Test plan

• go build ./...
• go test ./...

Had claude write a manual test:

• Creates a check
• creates a campaign
• copies the check to the campaign
• validates the check was copied & referenced & that the copy is returned in the result
• deletes the original check
• validates that the copy no longer references the original check.

func testCopyChecksToCampaign(client *opslevel.Client) {
	teams, err := client.ListTeams(nil)
	if err != nil || len(teams.Nodes) == 0 {
		fmt.Fprintln(os.Stderr, "list teams failed:", err)
		return
	}
	owner := teams.Nodes[0]
	fmt.Printf("owner team: %-40s %s\n", owner.Name, owner.Id)

	categories, err := client.ListCategories(nil)
	if err != nil || len(categories.Nodes) == 0 {
		fmt.Fprintln(os.Stderr, "list categories failed:", err)
		return
	}
	category := categories.Nodes[0]
	fmt.Printf("category: %-40s %s\n", category.Name, category.Id)

	levels, err := client.ListLevels(nil)
	if err != nil || len(levels.Nodes) == 0 {
		fmt.Fprintln(os.Stderr, "list levels failed:", err)
		return
	}
	for _, l := range levels.Nodes {
		fmt.Printf("available level: %-40s %s index=%d\n", l.Name, l.Id, l.Index)
	}
	level := levels.Nodes[len(levels.Nodes)-1]
	fmt.Printf("level: %-40s %s\n", level.Name, level.Id)

	sourceCheck, err := client.CreateCheckServiceProperty(opslevel.CheckServicePropertyCreateInput{
		Name:            "manual-test source check",
		CategoryId:      category.Id,
		LevelId:         level.Id,
		ServiceProperty: opslevel.ServicePropertyTypeEnumLanguage,
	})
	if err != nil {
		fmt.Fprintln(os.Stderr, "create service property check failed:", err)
		return
	}
	fmt.Printf("created source check: %-40s %s\n", sourceCheck.Name, sourceCheck.Id)

	campaign, err := client.CreateCampaign(opslevel.CampaignCreateInput{
		Name:    "manual-test campaign",
		OwnerId: owner.Id,
	})
	if err != nil {
		fmt.Fprintln(os.Stderr, "create campaign failed:", err)
		return
	}
	fmt.Printf("created campaign: %-40s %s\n", campaign.Name, campaign.Id)

	_, created, err := client.CopyChecksToCampaign(opslevel.ChecksCopyToCampaignInput{
		CampaignId: campaign.Id,
		CheckIds:   []opslevel.ID{sourceCheck.Id},
	})
	if err != nil {
		fmt.Fprintln(os.Stderr, "copy checks to campaign failed:", err)
		return
	}
	for _, check := range created {
		fmt.Printf("  created check: %-40s %s\n", check.Name, check.Id)
	}

	fmt.Println("validating sourceCheck before deletion...")
	if err := checkCampaignChecksSourceCheck(client, campaign.Id, sourceCheck.Id); err != nil {
		fmt.Fprintln(os.Stderr, err)
		return
	}

	if err := client.DeleteCheck(sourceCheck.Id); err != nil {
		fmt.Fprintln(os.Stderr, "delete source check failed:", err)
		return
	}
	fmt.Printf("deleted source check: %s\n", sourceCheck.Id)

	fmt.Println("validating sourceCheck after deletion...")
	if err := checkCampaignChecksSourceCheck(client, campaign.Id, ""); err != nil {
		fmt.Fprintln(os.Stderr, err)
		return
	}
}

// checkCampaignChecksSourceCheck lists a campaign's checks and verifies every
// check's SourceCheck.Id matches wantSourceCheckId (use "" to assert null).
func checkCampaignChecksSourceCheck(client *opslevel.Client, campaignId opslevel.ID, wantSourceCheckId opslevel.ID) error {
	campaignChecks, err := client.ListCampaignChecks(campaignId)
	if err != nil {
		return fmt.Errorf("list campaign checks failed: %w", err)
	}
	for _, check := range campaignChecks {
		fmt.Printf("  campaign check: %-40s id=%s sourceCheck.Id=%q sourceCheck.Name=%q\n",
			check.Name, check.Id, check.SourceCheck.Id, check.SourceCheck.Name)
		if check.SourceCheck.Id != wantSourceCheckId {
			return fmt.Errorf("FAIL: campaign check %s has sourceCheck.Id=%q, want %q",
				check.Id, check.SourceCheck.Id, wantSourceCheckId)
		}
		fmt.Println("    OK")
	}
	return nil
}