replace go objects with dicts in wind streaming example to improve perf

[michaelbabyn]

should help resolve #331.

After profiling this app with py-spy, this app running with a 5 tabs open spent 98% of the gunicorn resources updating graphs and most of that time was spent by plotly.py validating them. Getting rid of the go objects reduced the time spent updating the graphs to 33%

Before (using go objects)

After (using dicts)

Issue for app: #[issue number here]

App pull request

• This is a new app
• I am improving an existing app (redesigns/code "makeovers")

About

• Playground deployment URL (new version):
• Current gallery app URL: (delete this line if inapplicable)
• Python app repository link: (delete this line if you are working on a Python app)

Workflow

• I have created a branch in the appropriate monorepo, and the
  elements necessary for successful deployment are in place.
• If the app is a redesigned and/or restyled version of an
  existing gallery app, I've summarized the changes requested in the
  appropriate Streambed issue and confirm that they have been applied.
• If the app is on the Dash Gallery portal, I have added a link to
  the GitHub repository for the source code in the portal description.
• If the app is a reimplementation of a Python gallery app for the
  DashR gallery, the app in this PR mimics, as closely as possible,
  the style and functionality of the existing app.=
• I have removed all Google Analytics code from the app's
  assets/ folder.

The pre-review review

I have addressed all of the following questions:

• Does everything in my code serve some purpose? (I have removed
  any dead and/or irrelevant code.)
• Does everything in my code have a clear purpose? (My code is
  readable and, where it isn't, it has been commented appropriately.)]
• Am I reinventing the wheel? (I have used appropriate packages to
  lessen the volume of code that needs to be maintained.)

[shammamah-zz]

💃 Looks good to me

[michaelbabyn]

Cool. @shammamah , would you be able to merge? I don't have privileges to merge to this branch.