bugfix: federation fetch error

When a long request to a source of a federation is made, in some cases, we could see some errors in the console and the list never loads (it happens only when the federation is in a range).

With 1 component, it works fine:

• componentA.getData()
  • store gets https://api.community.hubl.world/sources/skills/
  • store caches https://api.community.hubl.world/sources/skills/
  • store finds a container inside, it fetches https://api.community.hubl.world/skills/
  • it waits...
  • when the request resolves, resolve getData

With 2 components, it can fail in this case:

• componentA.getData()
  • store gets https://api.community.hubl.world/sources/skills/
  • store caches https://api.community.hubl.world/sources/skills/
  • store finds a container inside, it fetches https://api.community.hubl.world/skills/
  • it waits...
• componentB.getData()
  • finds https://api.community.hubl.world/sources/skills/ in cache
  • gets the children
  • finds resource with id: https://api.community.hubl.world/skills/
  • gets https://api.community.hubl.world/skills/ from cache -> null
• componentA.getData() ...
  • resolves only now

Here is a test case:

    <solid-form
      id="form"
      data-src="https://api.community.startinblox.com/users/matthieu/"
      range-skills="https://api.community.hubl.world/sources/skills/"
      fields="skills"
      multiple-skills="solid-multiple-select"
      widget-skills="solid-form-auto-completion"
    ></solid-form>

    <solid-display
      id="display"
      search-range-skills="https://api.community.hubl.world/sources/skills/"
      search-fields="skills"
      search-widget-skills="solid-form-placeholder-dropdown"
      fields="first_name"
    ></solid-display>

    <button id="test">test</button>

    <script>
      test.onclick=() => {
        document.getElementById('display').dataset.src = "https://api.community.startinblox.com/users/";
      }
    </script>

To make it fails, we need the solid-display to load the skills when https://api.community.hubl.world/sources/skills/ has resolved. You can make it happen by clicking the test button as soon as the page loads.