add in_shape, defualt kwarg at WorkSheet::get method for resolving issue #947,

[ccppoo]

closes #947

method _inflate is for literally inflating json-body value got from Google spreadsheet API

by using _inflate it's possible to do the same for batch_get method,

but I'm making PR first then some one could do it instead of me ...

[ccppoo]

I have no idea whats wrong with linting, I'm getting nothing except venv package files and black is telling me All done
Help

[lavigne958]

Thank you @ccppoo for this contribution this is great work but I don't understand why you added a new method _inflate.
we already have a function that does the same job in gspread/utils.py:fill_gaps.
In that function we don't handle default values, so you simply need to add default values to it and you should be good to go.

remember that we never change what the API returns us, we take the values and create new structures but never change the original structure.

[ccppoo]

can't help myself with linting anymore, sorry

[lavigne958]

No worries. Did you think about what I said above ? What's your opinion on updating the function fill_gaps ?