Add execute-with-state overloads for correlated query profiling

[robsiera]

Why

QueryProfile can log query stats, but it has no way to receive per-call context (a request-scoped logger, correlation ID, or similar). Callers either use ambient/static state or lose the link between a specific Execute* call and its profile callback.

What

• Add optional object? state overloads for ExecuteAsync / ExecuteStreamAsync (existing overloads unchanged; they pass state: null).
• Add QueryProfileWithState on configuration: (query, bindVars, stats, returnCount, state).
• For non-stream execute, invoke profiling after the cursor is fully drained so returnCount matches the real result size; on failure pass stats: null and returnCount: -1.

Benefit

Pass any call-site object through to the profile callback—for example a scoped logger—without changing how the driver is shared application-wide:

config.QueryProfileWithState = (query, bindVars, stats, returnCount, state) =>
{
    if (state is ILogger logger)
        logger.LogInformation("Returned {Count} rows in {Time}s: {Query}",
            returnCount, stats?.ExecutionTime, query);
};

var result = await arango.Query.ExecuteAsync<MyDoc>(
    "database",
    $"FOR d IN docs RETURN d",
    logger);

Documented in the README; QueryProfileWithStateTest is a runnable usage example.

Test plan

• Build against supported TFMs
• Run QueryProfileWithStateTest
• Existing query tests still pass (overloads without state)
• Confirm QueryProfile and QueryProfileWithState both fire when configured