Listing Forecasters to be Refactored

[thayeylolu]

#955
We need to slowly re-factor all forecasters to be compliant with the new interface (see PR #912). i.e., no overrides of fit etc and descendant classes only implementing core logic, while the BaseForecaster implements check etc logic.

Currently this is running due to various downwards compatibility workarounds, which should be removed once all forecasters are ready (in "no-override" state)

The forecasters that still need a downstream refactor are:

• Forecasters in Italic text are failing test or CI

• Forecasters checked have been merged

• Forecasters in Bold text are in progress and have not been merged

• NaiveForecasters

• EnsembleForecaster

• MultiplexForecaster

• TransformedTargetForecaster

• _Reducer and related code

• StackingForecaster

• ForecastingGridSearchCV, RandomizedGridSearchCV, and BaseGridSearch

• OnlineEnsembleForecaster and descendants

• _PmdArimaAdapter and descendants ARIMA, AutoARIMA

• BATS, TBATS, and _Tbatsadapter

• _StatsModelAdapter and descendants AutoETS, ExponentialSmoothing, ThetaForecaster

• HCrystalBallForecaster

• Prophet and _ProphetAdapter

• PolynomialTrendForecaster

[fkiraly]

this is a duplicate of #955.

[Lovkush-A]

@fkiraly @thayeylolu I think Taiwo created this because we can't edit Franz's checkboxes in #955. (at least, I know that I cannot adjust them).

To get around this, I created checkboxes in the hackmd file for forecasting group of 2021 dev days. https://hackmd.io/84rpzQEiQiWQy5oQjs7FYw?view. The checkboxes are at the bottom of the hackmd file

It this is not a suitable solution, let me know

[fkiraly]

ah - well, I can simply update the checkboxes whenever a PR related to the root issue is closed?

Because I'd be reviewing them anyway.