Support union types and all templates in register_pre_build_hook

[daturkel]

Is your feature request related to a problem? Please describe.

Currently, if I want to apply a pre-build hook to both containers and scripts, I need to register the same hook twice, once for the Script type and once for Container. Similarly, there is no easy way to register a pre-build hook that will apply to all templates regardless of template type.

Describe the solution you'd like

1. Pre-build hooks should support union types, e.g.

ScriptOrContainer = TypeVar('ScriptOrContainer', bound=Union[Script, Container])

# This hook should be applied to scripts and containers
@register_pre_build_hook
def foo(template: T) -> T:
    ...

2. There should be an easy way to set a pre-build hook to support all template types.

Describe alternatives you've considered

The best alternative now is to define the hook in a native python function, and then wrap that function in a registered hook once per each type it needs to support.