Param.depends shorthand for “depends on all params”

I frequently end up adding/removing parameters to a parameterized Class, either by hand or by using them as parent classes later on. That means going through the entire class and updating all @param.depends(...) decorators, which quickly gets confusing especially when I have separate mixin classes for visualizations etc.

This could be solved by a shorthand for “this function depends on all params this class or its child classes might have”.

E.g. something like
```
@param.depends(all_params=True)
```
or even
```
@param.depends()
```
(Following up on https://discourse.holoviz.org/t/param-depends-shorthand-for-depends-on-all-params/270)