Improve UI/UX for Credential Selection Popup

[gkatrakazas]

Description
The current UI for the credential selection popup in the presentation module can be confusing for users, especially regarding the interaction required to select credentials. Users often struggle to understand that they need to click on the credential card to continue the process.

Suggested Enhancements

1. Opacity Adjustment for Credential Cards: Implement a visual distinction where all credential cards have a lower opacity by default. Increase the opacity of a card when it is selected. This will visually reinforce which credentials are currently chosen.
2. Continue/Next/Present/Send Button: Add a button at the bottom of the popup. This button will serve as a clear indicator for users to proceed after selecting their credentials.
3. Progression Step Bar: Introduce a step bar at the top of the popup to indicate the number of credentials required to be selected for the process. This will provide users with a clear sense of progress and expectation throughout the credential selection phase.

Expected Benefits
These improvements should make the credential selection process more intuitive and user-friendly. By enhancing visual cues and adding explicit navigation controls, we can help reduce user confusion and streamline interactions within the application.