[resource-graph] automatically paginate results

### Related command

az graph query

### Extension name (the extension in question)
resource-graph 2.1.0

### Description of issue (in as much detail as possible)
By default currently 100 results are passed as results to a query, you can increase this with --first to 1000. I would like an option to just get all results, no matter how many there are or how many pages it needs to paginate in background. Suggestion "--all" as new option.

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Start by locating the resource-graph extension's az graph query command and inspect how it handles --first and paged responses. Determine how an --all option should retrieve every page while preserving existing behavior, then verify that queries returning more than 1000 results produce the complete result set.

Written by the indexing model from the issue text.