fix(web-components): isolate radio option label targets

[sylvesterkaczmarek]

Summary of the changes

Fix repeated radio groups with identical labels so each option label targets the radio input in its own group.

Radio option IDs previously used the option label/value plus the radio-group label. When multiple groups shared the same label, equivalent options produced duplicate DOM IDs, so clicking a label in a later group could activate the first group's input.

The fix keeps existing IDs unchanged for ordinary single-group cases, but includes the required radio-group name when the same group label appears more than once on the page.

A focused regression test renders two groups with identical labels and verifies that all radio input IDs are unique and every label points to its own input.

Closes #4165

[GCHQ-Developer-530]

Hi, thanks for this contribution. Please could you run prettier to pass the CI build? Also please could you squash your commits into one, there should be one commit per scope e.g. web-components 😊 Thank you

[sylvesterkaczmarek]

@GCHQ-Developer-530 Thanks. I've applied the Prettier formatting fix and squashed the PR to a single web-components commit as requested. The new Actions runs are currently waiting for approval.

[lz405]

Thanks for contributing. We generally do not split test files per test, and keep tests grouped together per component.

[sylvesterkaczmarek]

Thanks for the guidance. I've moved the regression coverage into the existing ic-radio-group test file and kept the PR to a single web-components commit. The new Actions runs are currently waiting for maintainer approval.

[GCHQ-Developer-530]

Please rebase this branch