(WIP) Kafd share on forus

**Don't Merge**



Theme PR: https://bitbucket.org/Edraak/edraak-theme/pull-request/17/wip-share-on-forus-theme-changes/diff

New env/auth variables:

```
+# Edraak and KAFD/ForUs integration.
+FORUS_SECRET_KEY = AUTH_TOKENS.get("FORUS_SECRET_KEY")
+FORUS_ERROR_REDIRECT_URL = ENV_TOKENS.get("FORUS_ERROR_REDIRECT_URL", ())
+
```