[ic-loading-indicator] - Review styling of loading indicator in high contrast mode and of light variants

## Summary
The current styling of light variant ic-loading-indicator and in high contrast mode should be reviewed.

## 💬 Description
Currently, only the filled portion of the radial loading indicators is visible in high contrast mode. This is particularly a problem when there is no label and the progress is at 0. The same problem exists when the light variant is used.

High contrast:

Light variant:

The linear loading indicators have an outline, so there is no issue with the display in high contrast mode:

A solution may be to add an outline.

Start at the ic-loading-indicator component entry point and inspect how the radial indicator renders in high contrast mode and with the light variant. Compare its styling with the linear indicator, then verify that the unfilled portion remains visible at zero progress without a label in both affected cases.

Written by the indexing model from the issue text.