Function handle_will_send_keys

pub(crate) fn handle_will_send_keys(
    documents: &DocumentCollection,
    pipeline: PipelineId,
    element_id: String,
    text: String,
    strict_file_interactability: bool,
    reply: IpcSender<Result<bool, ErrorStatus>>,
    can_gc: CanGc,
)

Implementing step 5 - 7, plus part of step 8 of “Element Send Keys” where element is input element in the file upload state. This function will send a boolean back to webdriver_server, indicating whether the dispatching of the key and composition event is still needed or not.