feat(functions): Add more details to FunctionsError

[hsubox76]

Functions errors historically have not have a lot of detail which makes debugging difficult. We can't provide much more detail when it comes to network errors and native API "fetch errors", since they don't provide us with much information, but I am adding what we can.

1. Add the http status code into the message. I think a lot of the more mysterious failures will be 0, meaning a network or fetch error, which we don't have any further information on, so this might not be that helpful.
2. Add a url string in the customData field (customData is standard in all FirebaseError objects). This may help debug a nonexistent function name or region, for example.

Fixes #9807

[changeset-bot]

🦋 Changeset detected

Latest commit: 0131a85

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 3 packages

Name	Type
@firebase/functions	Minor
@firebase/functions-compat	Minor
firebase	Minor

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[gemini-code-assist]

Code Review

This pull request enhances FunctionsError by including the HTTP status code in the error message and adding url and details fields to customData. It updates the error handling logic in _errorForResponse and ensures the request URL is propagated through the error reporting chain. Feedback was provided regarding the FunctionsError constructor, specifically noting that direct assignment to customData might violate readonly constraints and that the current falsy check for details could skip valid values like 0 or false. It is recommended to pass the customData object directly to the super call instead.

[github-actions]

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