Add function to collect data_type and data_kind

[dachengx]

What is the problem / what does the code in this PR do

Add a function to return the collection of which data_type belongs to which data_kind.

slack thread

Can you briefly describe how it works?

Iterate through the strax.Conetxt._plugin_class_registry and init plugins by strax.Conetxt.__get_plugin to let strax.Context to assign the data_kind, then collect the results.

Can you give a minimal working example (or illustrate with a figure)?

In the test, the function get_data_kinds will return:

({'records': ['records'], 'peaks': ['peaks', 'cut_peaks']}, {'records': 'records', 'peaks': 'peaks', 'cut_peaks': 'peaks'})

Please include the following if applicable:

• Update the docstring(s)
• Update the documentation
• Tests to check the (new) code is working as desired.
• Does it solve one of the open issues on github?

Please make sure that all automated tests have passed before asking for a review (you can save the PR as a draft otherwise).

[coveralls]

coverage: 90.721% (+0.002%) from 90.719%
when pulling 5bd0f0e on data_kind_collection
into d66cd35 on master.

[yuema137]

@dachengx Thanks this looks good. I made a small modification to check the output in the test.