typing of tests

[Christian-B]

ConnectionHolder types updated to included list types.

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"Values" TypeAlias used for setting PyNn values such as State Values and parameter Values updated to include a callable to go from int to a float.

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The input types allowed for Weight and delays
spynnaker/pyNN/types.py
changed to allow NDArray of float.
removed "int" as float implies int

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added a writer _get_id_counter test method
as hacking the data and adding an ignore in 80 characters was too tricky

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Population / PopulationView all method type fixed.

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weight_scales can be numpy array or Sequence of float

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Type alias for mask used to create PopulationViews relaxed to accept any Sequence (for example a tuple)

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spynnaker_integration_tests/test_additional_params_on_pop_not_recogonised/test_additional_params_mix.py
Changed to include the checking of logs

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/home/brenninc/spinnaker/sPyNNaker/unittests/test_from_file_connector.py
replaced:
elif len(header):
f.write("# {}\n".format(header))
with:
else:
assert len(header) == 0
reason is the write of a string fails! but was never actually called!

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numpy.array_equal can compare None to None even though mypy thinks it can not