perf: optimize DataGridView scroll performance

[datlechin]

Summary

• Pre-compute per-column metadata (enum/set, foreign key) once when data changes instead of per-cell during scroll — eliminates ~600 dictionary lookups per scroll frame, replaced with O(1) Set.contains()
• Pre-warm display cache for the initial viewport on first data load — prevents formatting stalls (date parsing, line break sanitization) during first scroll
• Skip redundant cell property resets (lineBreakMode, maximumNumberOfLines, etc.) on reused cells when they haven't been modified by editing

Addresses #519

Test plan

• Open a table with 500+ rows, scroll rapidly — verify no lag or dropped frames
• Verify enum/set columns still show dropdown indicators correctly
• Verify foreign key arrow buttons still appear on FK columns
• Edit a cell, then scroll — verify reused cells still display correctly (single-line truncation)
• Switch between tabs and scroll — verify display cache works correctly