Deprecate the self.hparams setter in LightningModule
🚀 Feature
Modifiy the hparams setter method of LightningModule to print a warning when we make an assignment.
Motivation
Encourage users to use the self.save_hyperparameters() feature, which can handle hyperparameters better.
Directly assigning to self.hparams is not recommended.
Pitch
# let it print a warning
self.hparams = my_namespace

warning: assigning to self.hparams is deprecated and will be removed in 1.x.0. It is recommended to use self.save_hyperparameters()

and eventually remove the setter. Keep the getter property, user can still access hparams via
# still possible
x = self.hparams.batch_size
# still allowed
self.hparams["something"] = something
Alternatives
Keep as is. User has limitations / multiple ways  of doing the same thing.
cc: @Borda @rohitgr7