## Description

Fixes #3822

Added `getIndexOf(Tab)` as the replacement for the deprecated
`indexOf(Component)` and `indexOf(Tab)` methods, aligned with
`TabSheet.getIndexOf(Tab)`.

## Type of change

- Feature

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: Serhii Kulykov <10589913+web-padawan@users.noreply.github.com>