Rework oeo class page: Add OEO entity & OEO search pages

[jh-RLI]

Summary of the discussion

This PR implements the reworked former OEO Class now OEO Entity page to find details about an entity availabe in the OEO when navigating to its IRI.

Additionally we intorduce a new OEO Search page which helps to browse the OEO Enities and find its IRI pages.

This is all done in React using the TSS Widget lib.

Type of change (CHANGELOG.md)

Features

• Add a new OEO search page for simple search and browsing of OEO entities
  (#2234)
• Add interactive parent/child hierarchy navigation and IRI copy functionality to entity detail pages
  (#2234)

Changes

• Reworked the former OEO Class pages into OEO Entity pages, now supporting details for Classes, Properties, and Individuals
  (#2234)
• Integrated NFDI4Energy Terminology Service Suite (TSS) React widgets for standardized search, metadata, and relations displays
  (#2234)
• Improved IRI resolution to seamlessly handle and route external/imported ontology terms (e.g., OBO Foundry)
  (#2234)
• Implemented client-side React routing (SPA) for seamless transitions between search results and entity details
  (#2234)

Removed

• Removed the previous custom backend and frontend implementation for the OEO Class / IRI pages
  (#2234)

Workflow checklist

Automation

Closes #1911
Closes #2088

PR-Assignee

• 🐙 Follow the workflow in
  CONTRIBUTING.md
• 📝 Update the
  CHANGELOG.md
• 📙 Update the documentation on
  mkdocs

Reviewer

• 🐙 Follow the
  Reviewer Guidelines
• 🐙 Provided feedback and show sufficient appreciation for the work done