Individual mock options are not taken into account

[javihernandez]

If a build is created using this payload:

{
  "platforms": [
    {
      "name": "AlmaLinux-8",
      "arch_list": [
        "x86_64"
      ],
      "parallel_mode_enabled": true
    }
  ],
  "tasks": [
    {
      "git_ref": "a8",
      "url": "https://git.almalinux.org/rpms/almalinux-release.git",
      "ref_type": 1,
      "mock_options": {
        "module_enable": [
          "nodejs:12"
        ]
      },
      "test_configuration": {}
    }
  ],
  "linked_builds": [],
  "is_secure_boot": false,
  "mock_options": {},
  "platform_flavors": [],
  "test_configuration": {},
  "product_id": 1
}

The mock config generated for the package to be built doesn't include the enabled module. We need to ensure that individual mock mock configs are properly applied.