[Enhance] Update reload_dataloaders_every_epoch to reload_dataloaders_every_n_epoch

[rohitgr7]

🚀 Feature

reload_dataloaders_every_epoch reloads dataloader every epoch. We can change it to reload dataloaders after every n epochs. It will accept both bool and int values. True will be treated as 1 and False will be treated as 0 (means no reload).

Motivation

Recently a request came up on slack regarding reloading dataloaders after some epochs. Also since we have enhanced fast_dev_run like this, we can update this too.

Alternatives

Can be done manually by calling the method to reload dataloaders with a simple conditional statement by setting reload_dataloaders_every_epoch=False, but we can let this attribute accept an integer to avoid manual work.

[rohitgr7]

cc @PyTorchLightning/core-contributors is this a good feature to have??

[stale]

This issue has been automatically marked as stale because it hasn't had any recent activity. This issue will be closed in 7 days if no further activity occurs. Thank you for your contributions, Pytorch Lightning Team!