fix: do not force showing notices with hidden class

[matzeeable]

Summary

Your implementation to always show notices also shows notices from other plugins.

Actual Behavior

All notices (also hidden) from other vendors are always visible.

Steps to reproduce

• Install https://wordpress.org/plugins/real-media-library-lite/
• Navigate to your Admin Column settings page

Real Media Library shows a notice for failing WP REST API requests (using the WP Core class .hidden).

Proposal

Do not force showing notices with explicit .hidden class.

Environment

Not relevant.

[DGStefan]

@matzeeable Thanks for your input. I've merged your PR to the repo.

[matzeeable]

Thanks!