Add "include" Query Parameter

[fvanderflier]

The query parameter should look something like mydappiapi/authors?include=books, books.editions

Acceptance Criteria

• The query param is parsed and validated in an Action filter, and attached to the current HttpContext. Take a look at: feat: extensive filters #200 for an idea.
• This should be done in accordance to Create a dynamic repository #265 . Meaning that the action filter should map the query parameter to something useful to the repository.