[dbapi] Stop shadowing exceptions in get_repository() (closes #2710515)
Exceptions are already handled higher up in the stack so there's no
reason to handle them here. Furthermore, non-ConnectionError exceptions
would get hidden, making debugging harder.
Add some entities
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As manager, you can access to entity creation forms by using the `site management`_ page.
.. _`site management`: manage
As regular user, the index page or the action box may propose some links to create entities according to the context.