Apim 11513 implement UI design

[jourdiw]

Issue

https://gravitee.atlassian.net/browse/APIM-11513

Description

This Pull Request enhances the UI and interaction features for the tree component in the Gravitee APIM Console Web UI. It introduces accessibility improvements, code refactoring, design adjustments, and panel resizing functionality for better user experience and maintainability.

• Updated tree component (tree-node.component) with better accessibility attributes (e.g., aria-expanded, aria-selected) and smoother interactions through event handling.
• Introduced new SCSS styles with modernized design (e.g., material theme, revised padding/margins, responsive layout adjustments).
• Added resizing functionality for the navigation panel (portal-navigation-items.component) with minimum and maximum width constraints.
• Cleaned up redundant HTML and CSS elements for better structure and performance (e.g., removed outdated classes, card wrappers in certain templates).
• Refactored and updated related unit tests to reflect UI changes (e.g., selector updates for test cases).

Screen.Recording.2025-11-25.at.16.02.09.mov

Additional context

[jourdiw]

/gemini review

[gemini-code-assist]

Code Review

This pull request brings significant UI and interaction enhancements to the tree component and introduces a resizable navigation panel. The changes include modernizing styles, improving accessibility attributes, and refactoring for better maintainability. The code quality is high, especially the implementation of the panel resizing logic which correctly uses NgZone for performance. I have a few suggestions to further improve accessibility, correctness, and code consistency.

[jourdiw]

responses!