[Feature Request]: Add real-time search filter and "New File" context menu to the File Explorer (CTRL+O)

### What would you like to happen?

Current Situation
Currently, when using the Explorer Perspective (often accessed via CTRL + O), users with large projects find it difficult to locate specific pipelines (.hpl) or workflows (.hwf). The interface lacks a quick way to filter the list and requires manual navigation through folders to create new resources.

Proposed Improvements
1. Real-time Search Filter
Location: Add a search input field at the top of the File Explorer view.

Functionality: As the user types, the file list should automatically filter in real-time.

Search Scope: It should match filenames (case-insensitive) while keeping the parent directory structure visible for context.

2. "New File" Context Menu
Functionality: Add an option when right-clicking an empty area or a folder within the Explorer to "Create New Pipeline" or "Create New Workflow".

Benefit: This eliminates the need to go back to the main menu or toolbar, speeding up the development workflow.

Expected Behavior
A user hits CTRL + O, starts typing "stage_p...", and immediately sees only the files matching that prefix.

The user can right-click a folder in that same view and create a new file immediately.

Screenshots / Mockups

### Issue Priority

Priority: 3

### Issue Component

Component: Hop Gui

Start with the Hop GUI Explorer Perspective opened through CTRL+O and trace the File Explorer view's existing file listing and context-menu entry points. Implement the requested filename filter and new pipeline/workflow actions while preserving parent directories; done means matching files update as the user types and folder or empty-area context menus can create both resource types.

Written by the indexing model from the issue text.