Allow to enable / disable temporarily a feature

As a user, when I am editing a feature, I can see a toggle button.

• This toggle button is placed in a consistent manner, e.g. next to the feature name.
• Clicking that toggle button switches the feature state from enabled to disabled and vice versa.
• By default the feature state is "enabled" when I create it.

When the feature is switched to the disabled state:

• The feature is saved:
  => in simple mode, this generates a commit and push just as if I pressed the save button.
  => in intermediate / advanced mode, this acts as if I pressed the "save work in progress" button. The user needs to commit / push manually.
• In the feature screen, a message tells me "This feature is currently disabled. It will not be available when deploying your configuration, and Studio will behave as if it doesn't exist."
• An overlay prevents me from changing the feature.
• A visual indicator on the left tree lets me know that this feature is disabled (add a class on each disabled feature in tree + styles).
• Nuxeo Studio acts as if the feature does not exist and displays validation errors on the features that depend on the disabled one. Exactly as if I deleted the feature.
• The feature is not available anymore in the bundle generated by Nuxeo Studio.

When the feature is switched to the enabled state:

• The feature is saved:
  => in simple mode, this generates a commit and push just as if I pressed the save button.
  => in intermediate / advanced mode, this acts as if I pressed the "save work in progress" button. The user needs to commit / push manually.
• The overlay disappears and I can change the feature again.
• In the left tree, the feature style is back to normal.
• Nuxeo Studio acts as if the feature exists and does not display a validation error on features depending on it (e.g. if I reactivate a chain that is triggered by a user action, the user action does not display an error message anymore).
• The feature is available in the bundle generated by Nuxeo Studio.

This feature impacts:

• Branding
  => The "Disable theme branding" option should be removed, as this feature replaces it.

• Users & Groups Definition
  => The "Disable users and groups definition" option should be removed, this feature replaces it.

WARNING: This feature will also be used to see if a feature has many links and relations or not, to see if you can remove a feature without breaking your application