Create a way to evaluate arbitrary javascript

Current Situation

Currently, there is no method to transmit the results of a JavaScript function to the backend.

Proposed Actions

This might look like a use_script hook that operates similarly to html.script, but can return a result.

For example,

@component
def example():
    executor = use_script("getComputedStyle(document.querySelector('#element'))")
    return f"CSS Style Attributes: {executor.data}"

Since this hook would need to operate asynchronously, the interface would likely be heavily inspired by our Django use_query hook.

And perhaps it could be used as an executor within event contexts to be more "reactive":

@component
def example():
    executor = use_script("getComputedStyle(document.querySelector('#element'))", deferred=True)

    async def on_click(event):
        await executor()
        example_value = executor.data 

    return f"CSS Style Attributes: {script.data}"

See this comment for traceability.

Note: If possible, we should try pre-populate this keyword with something that makes sense, depending on where the JavaScript was executed.

Start by reading the existing html.script and Django use_query hooks, then review the traceability comment in issue 857. Define how use_script should return JavaScript results, support asynchronous or deferred event execution, and handle the this keyword. Done means the proposed examples have a clear, working interface.