Creating derived model breaks when the schema has no title.

[darrelmiller]

The EndsWith method fails when title is null.

kiota/src/Kiota.Builder/KiotaBuilder.cs

Lines 759 to 760 in 4d148ba

	if(parentSchema.Reference?.Id?.EndsWith(title, StringComparison.OrdinalIgnoreCase) ?? false) return parentSchema.Reference.Id;
	if(parentSchema.Items?.Reference?.Id?.EndsWith(title, StringComparison.OrdinalIgnoreCase) ?? false) return parentSchema.Items.Reference.Id;

    baseObject:
      type: object
      discriminator:
        propertyName: kind
      properties:
        name: { type: string }
        kind: { type: string }
    derivedObject:
      allOf:
      - $ref: "#/components/schemas/baseObject"
      - type: object
        properties:
          special: { type: string }