[TwigComponent] Allow Index view for Anonymous Components

[seb-jean]

Q	A
Bug fix?	no
New feature?	yes
Tickets	Fix #1060
License	MIT

I created this PR using the example on laravel/framework#38847.

Currently we can get the code below but the Accordion and Item template will not be in the same directory.

<twig:Accordion>
    <twig:Accordion:Item>...</twig:Accordion:Item>
    <twig:Accordion:Item>...</twig:Accordion:Item>
</twig:Accordion>

But we could do it by doing <twig:Accordion:Accordion> but that's weird.

With this functionality, it allows you to structure the components well. Here we will then have:
components/Accordion/Index.html.twig
components/Accordion/Item.html.twig

[smnandre]

Not needed here i think (legacy behaviour)

[smnandre]

On one hand, i clearly see the DX benefit for front-end development.

On the other hand, this break some things / raise some questions:

• we cannot "just add a class Accordion.php" to add PHP computation.. because the associated template would be "Accordion.html.twig" and that was a big need for the anonymous
• a component can be called by two names now (twig:Accordion and twig:Accordion:Index)
• the debug / suggest tools will have more checks to do

None of those are blocking points, but that deserve a bit of thinking i guess.

Update: that also would create two separate behaviour (depending of class-based or anonymous component)

[seb-jean]

Thank you for your answer

[seb-jean]

@smnandre Do you know how to move forward with this PR?

[WebMamba]

I am sorry but I am not sure about this PR. Because of the reasons @smnandre mention and I don't like the idea of adding new conventions. We want people to feel free to write their code how they wanted without looking at conventions. This PR: #1209 could be a solution for your issue. We just have some fix to do before it get merged 😁