Continual-inference

Added
- Add `forward_shrink` option to `Delay` and `Residual`.

Added
- Add `Constant`.
- Add `Zero`.
- Add `One`.

Fixed
- `co.ConvXd` cuda compatibility.

Added
- Add `flatten_state_dict` state variable.

Removed
- Debug message for Convolutions with padding.

Fixed
- `call_mode` for `Linear`.

Added
- Add `call_mode`.
- Add `warm_up`.

Changed
- Container implementations to use `__call__` with alternating call_modes. This change was necessary to properly trigger the torch hooks needed in `ptflops`.

Fixed
- `ptflops` compatibility.