[website] Link respective repositories in product pages

[sidtohan]

• Modified AppHeader.tsx to detect the current product and link the github icon to the appropriate repository.

Fixes #34336

A continuation of #34889

[mui-bot]

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[sidtohan]

@oliviertassinari can you have a look at this? I have removed concatenation as you suggested.

[oliviertassinari]

@sidtohan Thanks, I have pushed a few changes with the goal to simplify the implementation. It seems that we can give control to the page that renders these components. I think it's simpler (e.g. won't break when the URL changes) but it's not for me to carry forward so I'm leaving the PR. I'm adding as reviewers the two people that were involved in the GitHub issue.

If we move forward with this approach, this will need to be updated: https://github.com/mui/mui-toolpad/blob/213103a8b1dd1a877939b083fb833aeef35e2ec1/docs/pages/toolpad/index.js#L41. @bharatkashyap Could you take care of it? Thanks cc @Janpot who raised the confusion during a Toolpad's meeting.