tabular_data_preview: Extract table component from the preview pane

[HalavicH]

TL;DR

TabularDataPreviewPane did rendering, focus, engine, and settings all in one component.

Extracted the table-rendering half into TableView (new table_view.rs), so the pane now owns tab/item concerns and just embeds self.table: Entity<TableView> which allows the table to be reusable in other contexts (i.e. multiple tables per pane or rendering data from other sources like DB client).

NOTE: No behavior changes. Only refactoring

Testing

• cargo check -p tabular_data_preview, ./script/clippy clean.
• Tested manually: no UI/UX/performance regressions

Self-Review Checklist:

• I've reviewed my own diff for quality, security, and reliability
• Unsafe blocks (if any) have justifying comments
• UI standards followed
• Tests cover the new/changed behavior
• Performance impact considered, acceptable

Release Notes:

• N/A