[data grid] Icon usage enhancements

[michelengelen]

2. Theming – Icons

👉 (All in one) Code Example

2.1 Missing centralized replacement points

• Some icons (e.g., Pagination) can only be replaced directly on the component, not via DataGrid slots.
• This is inconsistent and inconvenient.

2.2 Inconsistent slot naming

FilterPanel

• filterPanelRemoveAllIcon
• filterPanelDeleteIcon

Mixing “Remove” and “Delete” is confusing.
💡 Suggestion: consistent naming + a single point of configuration.

Column Selector / Menu

• columnSelectorIcon
• columnMenuManageColumnsIcon

Both open the same menu but must be replaced separately.

Positive example:

• quickFilterIcon — set once, used in multiple places (Toolbar search and ColumnMenu search).

2.3 Inconsistent icon logic in similar features

• Pinned Left/Right: One icon that disappears when unpinned.
• Grouping: Changes between “Group” and “Ungroup” icons.

💡 Suggestion: unify icon logic so similar actions use similar patterns.

[KrishCodesw]

@michelengelen Can you please assign this issue to me ?