FinOps utilization data not clearing on server switch

[erikdarlingdata]

Bug

When switching servers on the FinOps Utilization tab, stale data from the previous server remains visible in grids and charts. The "No utilization data" message also renders in the wrong position (overlapping content).

Impact

• Users see misleading data from the wrong server
• "No utilization data" message appears at wrong vertical position

Root cause

1. No else branch to clear grids (TopTotalGrid, TopAvgGrid, DbSizeChart, ProvisioningTrendGrid) when utilization data is unavailable
2. NoUtilizationMessage had incorrect Grid.RowSpan and VerticalAlignment in XAML

Fix

• Add else branch to clear stale grid data on server switch (both Dashboard and Lite)
• Fix XAML layout: RowSpan="4", VerticalAlignment="Top", Margin="0,20,0,0"

[erikdarlingdata]

Fixed in PR #534