Implement broadcast arrays

[djpugh]

• [x] Improves #981
• [x] Executed pre-commit run --all-files with no errors
• [x] The change is fully covered by automated unit tests
• [x] Documented in docs/ as appropriate
• [x] Added an entry to the CHANGES file

[MichaelTiemannOSC]

I think I need this. I want to be able to broadcast a quantity to a dataframe thusly:

x['foo'] = Q_(1.0, ureg('m'))

Presently I get this error message:

TypeError: object of type 'int' has no len()

If I manually create a PintArray based on the length of X and do some extra work I can cause my scalar quantity to become part of the X dataframe. But a broadcast feature would be wonderful.

[djpugh]

@hgrecco - the previous tests failed on install of uncertainties==3.0.1

[keewis]

TypeError: object of type 'int' has no len()

Note that you can work around this by setting ureg.force_ndarray_like = True or ureg.force_ndarray = True

[djpugh]

@hgrecco this seems to be passing and ready to merge - any other comments?