Various improvements

[frankrousseau]

Problem

• There is no way to set the difficulty of a task
• Depending on project configuration, the publish tab should be displayed by default to artists
• We can't know who is the author of a shared filter.
• It's not possible to set the Kitsu as dark by default for every one.
• Notifications are missing filters and could be neater.

Solution

• Add a difficulty field to tasks.
• Add a setting to show the publish tab by default for the artists.
• Add a title to show the author of a shared filter.
• Add a setting to set the dark theme as default.
• Add read / unread and watching / is not watching filters to the notification page.
• In notifications, show only main information by default and show comments on the selection or in show comments mode.
• Allow to mark notifications as read/unread and do not mark them as read automatically.

[NicoPennec]

The currentProduction value may be incorrect on global pages (My Tasks, My Checks, News Feed, ...).

You can use this.productionMap.get(task.project_id) to retrieve the production of the current task.

[frankrousseau]

Thx. It's fixed.