[ic-dialog] V2: Tabs Focus issue

### Summary of the bug
V2 partner ticket to https://github.com/mi6/ic-ui-kit/issues/3658

We're concerned that this will be more complex than the V3 fix due to differences in dialog code

Start by reading the linked partner issue #3658, then locate the V2 ic-dialog implementation and compare its dialog code with the V3 fix referenced by the issue. Done means the V2 tabs-focus problem is addressed despite the dialog-code differences.

Written by the indexing model from the issue text.