Adding dynamic tabs

The dynamic tabs are an extension (and replacement, once it has similar level of functionality) for the existing external reputation system (which is somewhat specialized and not well-documented).

Assumptions:

• Each Epic operator will be able to configure any (there may be soft warnings, though, if someone goes overboard) number of customizable tabs to be filled with any data
• The tab would, in the MVP version, have a title (spread across existing language versions) and a big text field for content (entered manually, JSON-based, akin to current take on CharacterSheet)
• The content would be then interpreted according to the rules and rendered into a simple HTML structure to be displayed - headers, text, tables, lists
• The content would have to be filtered for <script>, <iframe>,and other suspicious tags for safety; consider whether filtering links out is also reasonable
• The tabs would be displayed between the default tabs (Descriptions and Organizations) and GM Data (which is supposed to always be on the end); until Reputation tabs are decommissioned, they will precede the custom tabs as well
• Display order would be decided via configuration
• Since this is configured on the Epic level, there should be a choice how to display a tab when there is no data - an empty tab with a message, or no tab at all
• Initially, this will be done for Character

Possible extensions:

• Adding an option to replace the manual input with an API call configuration, with URI and time between calls (manual "call now" button included, disabling automatic calls also possible); the possibility to edit the API-provided payload locally would be retained
• Copying the solution for Group
• Copying the solution for Story
• Adapting the current CharacterSheet to use this solution instead
• A possibility to create multiple tabs with a single configuration (adding another level in the payload structure)