WebSearch: add bibdocs to record context
installation: initial upgrade recipe for next

* Create WebDeposit tables.
WebStyle: new config option CFG_SITE_SECRET_KEY

* Adds CFG_SITE_SECRET_KEY to set the Flask config variable
  SECRET_KEY on a per-site base. The variable should be used to
  e.g. protect against cross-site request forgery.
WebStyle: nice error page view decorator

* Add flask view decorator that will catch specific exceptions and
  render a nice error page for the end-user. The decorator is
  complementary to the normal Flask error handlers for 404 and 500
  HTTP errors.
WebStyle: catch HTTPS redirects in debug toolbar

* Move loading of Flask Debug Toolbar just before SSLify to
  catch HTTPS redirects.

* FIXME flask_sslify should work in debug mode as well (see #1325)

Co-authored-by: Jiri Kuncar <jiri.kuncar@cern.ch>