now the unauthenticated messages are only shown on the settings page. T…

[gin0115]

…he notice of invalid API creds, doenst show if no keys entered, only if we have keys and they are wrong.

Changes proposed in this Pull Request

This pull request refines how unauthenticated and invalid API credential notices are displayed in the Link Fixer plugin. It ensures that users only see relevant warnings, improves the logic for showing/hiding messages, and clarifies that providing API credentials is optional for higher limits. The changes focus on better user experience in both the dashboard and settings wizard.

User notice improvements:

• The unauthenticated mode notice is now dismissible, enhancing user experience in the admin area.
• The dashboard widget no longer displays the unauthenticated mode warning, reducing redundant messaging to users.

Settings page logic and messaging:

• The settings page now only shows the "invalid API keys" warning if credentials are entered but invalid, and hides it entirely if both keys are empty.
• The CSS class logic for API key fields was updated to avoid marking fields as invalid when both keys are empty, ensuring clearer feedback to users. [1] [2]

Wizard improvements:

• The wizard step now clarifies that entering API credentials is optional for unlocking higher limits.

Testing instructions

Mentions #241