Reduce dependency on getdkan/contracts (part 1)

[paul-m]

Fixes #3821

Old interface	New interface
\Contracts\CountableInterface	\Countable
\Contracts\HydratableInterface	\Procrastinator\HydratableInterface
\Contracts\ParserInterface	\CsvParser\Parser\ParserInterface

\Contracts\RetrieverInterface and \Contracts\StorerInterface remain in getdkan/contracts because there is no clear place to move them. They're needed within multiple libraries.

We also need to keep getdkan/contracts as a dependency in many places because some libraries use Contracts\Mock\Storage\Memory for tests.

Our changes to Drupal\common\Storage\Query... See the @todo which asks if we should just make a QueryInterface.

In order to make all these changes, we have to modify the following libraries, maybe in this order.

Each PR is a branch named no-contracts, some of which have interdependencies on each other. These PRs will need to be updated to require the release of each of these dependencies.

Package	Comment	PR
getdkan/contracts	Deprecates all the interfaces changed above (for now).	GetDKAN/contracts#16
getdkan/csv-parser	Has no dependencies on getdkan/contracts after PR.	GetDKAN/csv-parser#20
getdkan/file-fetcher	Uses Contracts\Mock\Storage\Memory for testing.	GetDKAN/file-fetcher#39
getdkan/harvest	Uses Contracts\Mock\Storage\Memory for testing.	GetDKAN/harvest#20
getdkan/procrastinator	Uses StorerInterface and RetrieverInterface. We need to figure out where to put storage-related interfaces.	GetDKAN/procrastinator#23