Add repository filtering based on query string

[afuetterer]

Tasks

• add _build_query_params function
• add query to list function
• add query_params to _request function
• add --query to cli
• add tests
• valid query that returns repositories, e.g. biosharing
• invalid query that returns empty list, e.g. XXX
• mypy passes

What?

We want to be able to make calls like this:

re3data.repositories.list(query="biosharing")

which is translated to

https://www.re3data.org/api/beta/repositories?query=biosharing

How?

We need to build a query/params dict somewhere. Dict contains only non empty values. In this issue only query or nothing.

This affects the RepositoryManager and Client classes.