fix: named tab being required in generated types without any required fields

[paulpopus]

For this given config

{
  type: 'tabs',
  tabs: [
    {
      label: 'unnamedTab',
      fields: [
        {
          type: 'text',
          name: 'fieldInUnnamedTab',
        },
      ],
    },
    {
      label: 'namedTab',
      name: 'namedTab',
      fields: [
        {
          type: 'text',
          name: 'fieldInNamedTab',
        },
      ],
    },
    {
      label: 'namedTabWithRequired',
      name: 'namedTabWithRequired',
      fields: [
        {
          type: 'text',
          name: 'fieldInNamedTab',
          required: true,
        },
      ],
    },
  ],
},

The generated types should be

fieldInUnnamedTab?: string | null;
namedTab?: {
  fieldInNamedTab?: string | null;
};
namedTabWithRequired: {
  fieldInNamedTab: string;
};

Currently namedTab will be required as well without having any required fields, this fixes that.

Type of change

• Bug fix (non-breaking change which fixes an issue)