[BUG] disable autocomplete in the date pickers input

[AnnMarieW]

The dcc.DatePickerSingle and dcc.DatePickerRange inputs should set autocomplete='off'.

I don't think an autocomplete prop should be added since I can't see a use-case for changing it.

I can do a PR if you like.

Here is an example from the dash docs:

[T4rk1n]

I can do a PR if you like.

Thanks for the report, that would be appreciated.