New API to define triggers

[Lendemor]

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Type of change

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Changes To Core Features:

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Description

Change the API for defining the signature expected for any event triggers (uncontrolled or controlled):

def get_event_triggers(self):
    return super().get_event_triggers() | { 
        "trigger_name": lambda: [], #uncontrolled 
        "trigger_name": lambda e0: [e0], #1 args 
        "trigger_name": lambda e0,e1: [e0, e1.target.value], #2 args or more
    }

Deprecate the following : get_controlled_triggers, EVENT_ARG, get_triggers, EventChain

Also remove the unused and not working component CopyToClipboard

[masenf]

This looks awesome!

[masenf]

Love the new API. This is great!

[picklelo]

We could define a type Callable[Var, List[Var]] for the lambda type and use that instead of Any. Also, when would Var be the dictionary value type, wouldn't it always be a Callable?

[Lendemor]

I put Any because my previous definition using LambdaTypes was causing a lot of pyright errors.

Also the Union[Var, ...] is for backward compatibility until removal of deprecated features.

[masenf]

re-approve