Add ConfirmView utility

[TrustyJAID]

closes #6174

Description of the changes

Have the changes in this PR been tested?

Yes

[flaree]

Would it be worth adding an on_timeout that sets the buttons to disabled?

[TrustyJAID]

I am open to customizing the timeout but I will not be adding support for disabling the buttons automatically. That would require sending the message through the view which I feel takes away from the simplicity of this. The buttons when interacted with will remove the buttons from the message but timeout will do nothing and it should be up to the user to handle that I think.

[flaree]

Huh, I have a confirm that doesn't send through a view and works fine.

async def on_timeout(self):
        for item in self.children:
            item.disabled = True

[TrustyJAID]

That would disable the button and prevent any response but would still require editing the original message which this does not have any reference to.

[TrustyJAID]

I have reworked this slightly so we can know if the buttons were not pressed so users can clean them up however they wish, whether that be disabling the buttons or removing them after the timeout.

[Jackenmen]

It shouldn't be required (i.e. we should only try doing it if not None) but I think that it would be simple enough to allow setting view.message attribute after the message is sent and remove the view from the message on_timeout in such a case. I would also suggest updating the relevant example to use that, i.e.

view = ConfirmView(ctx.author)
view.message = await ctx.send("Are you sure you about that?", view=view)
await view.wait()
if view.result:
    await ctx.send("Okay I will do that.")
else:
    await ctx.send("I will not be doing that then.")

[Jackenmen]

There's mostly a bunch of docstring fixes left but I also commented with one implementation question.

[Jackenmen]

This new utility works as expected so from my side, this is good to go.

I would, however, like you to look at the rendered documentation and assess whether the current version of it is acceptable:
https://red-discordbot--6176.org.readthedocs.build/en/6176/framework_utils.html#redbot.core.utils.views.ConfirmView

Basically, I looked at the rendered documentation and thought that showing the documentation from the base class on our overridden version of the methods was confusing and have instead opted to document it with the actual behavior of them. Additionally, I documented confirm/dismiss_button as a regular attribute of the Button type since that's what it actually ends up being on the instance of this view.

If everything seems fine to you, feel free to just merge this.