Implement Secure Inputs for Dexcom and Nightscout Credentials

[bjorkert]

PR: Implement Secure Inputs for Dexcom and Nightscout Credentials

Closes #417

Description

This pull request addresses the issue of sensitive credentials (Dexcom password and Nightscout token) being displayed in plain text in the settings views. To enhance security and user privacy, the standard TextField has been replaced with the existing TogglableSecureInput component for these fields.

Changes Made

1. DexcomSettingsView.swift:

   • Replaced the TextField for the password with TogglableSecureInput.
   • Wrapped the "User Name" and "Password" rows in HStacks for consistent UI alignment.

2. NightscoutSettingsView.swift:

   • Replaced the TextField for the "Access Token" with TogglableSecureInput.
   • Updated the layout to use an HStack for better alignment of the label and the input field.
   • Changed the label from "Token" to "Access Token" for clarity.

Impact

• Improved Security: Passwords and tokens are now masked by default, preventing them from being accidentally exposed.
• Enhanced User Experience: Users can toggle the visibility of the credentials using the familiar "eye" icon, providing both security and convenience.
• Code Consistency: Leverages an existing custom component (TogglableSecureInput) for a consistent approach to handling secrets across the app.

This resolves the concerns raised in issue #417 by ensuring all sensitive credential fields are properly secured.

[marionbarker]

Code Review

Looks reasonable.

Test

Built this branch and the token (for NS) and the password (for Dexcom Share) are both hidden by default and can be revealed with a tap on the eyeball.