[data grid] Fix column aggregation breaking

[sai6855]

closes #19370

Before

https://stackblitz.com/edit/github-p76sjn2j?file=src%2Fdemo.tsx

After

https://stackblitz.com/edit/7ejhgqyd?file=src%2FDemo.tsx

Root Cause

When data loads asynchronously:

1. Grid initializes with 0 rows → aggregation calculates empty lookup {} and marks as applied
2. Rows finish loading → rowsSet fires → triggers aggregation
3. Sorting reapplies → sortedRowsSet fires immediately after → triggers aggregation with reason: 'sort'
4. Due to useRunOncePerLoop batching, only ONE runs - the 'sort' one
5. Optimization logic skips: reason === 'sort' && !needsSorting && hasApplied → returns early
6. Result: aggregation stays empty forever

Solution

• Track if aggregation has been applied at least once (hasAppliedAggregationRef)
• On rowsSet event, reset the flag to false
• This ensures aggregation must recalculate when rows load, even if a sort event immediately follows

Why the optimization is still needed

The optimization prevents unnecessary recalculations when sorting columns that don't have applySorting: true (like
sum, avg, etc.). The fix preserves this while ensuring we never skip the initial calculation after data loads.

[mui-bot]

Deploy preview: https://deploy-preview-19891--material-ui-x.netlify.app/

Bundle size report

Bundle	Parsed size	Gzip size
@mui/x-data-grid	0B(0.00%)	0B(0.00%)
@mui/x-data-grid-pro	0B(0.00%)	0B(0.00%)
@mui/x-data-grid-premium	🔺+92B(+0.01%)	🔺+51B(+0.03%)
@mui/x-charts	0B(0.00%)	0B(0.00%)
@mui/x-charts-pro	0B(0.00%)	0B(0.00%)
@mui/x-charts-premium	0B(0.00%)	0B(0.00%)
@mui/x-date-pickers	0B(0.00%)	0B(0.00%)
@mui/x-date-pickers-pro	0B(0.00%)	0B(0.00%)
@mui/x-tree-view	0B(0.00%)	0B(0.00%)
@mui/x-tree-view-pro	0B(0.00%)	0B(0.00%)

Details of bundle changes

Generated by 🚫 dangerJS against a994508

[lauri865]

I have an alternative fix here: #19892

The issue is that it cancels too early if it's due to sorting. But there's another performance improvement I introduced there.