Add support for external needs in PlantUML drawing

[4og]

📌 Description

When attempting to draw UML diagram with draw_component() where external needs are referenced, the documentation build fails with a Python exception coming from the get_need_link function.

According to https://sphinx-needs.readthedocs.io/en/latest/api.html#sphinx_needs.data.NeedsSourceInfoType, external needs do not define the docname field, which is used in the HTML link construction. This PR extends the get_need_link with the support for external needs.

🚨 Impact Analysis

• This change does not violate any tool requirements and is covered by existing tool requirements
• This change does not violate any design decisions
• Otherwise I have created a ticket for new tool qualification

✅ Checklist

• Added/updated documentation for new or changed features -> minor change, no update needed
• Added/updated tests to cover the changes -> there is no test infrastructure for component drawing.
• Followed project coding standards and guidelines

[github-actions]

License Check Results

🚀 The license check job ran with the Bazel command:

bazel run //src:license-check

Status: ⚠️ Needs Review

Click to expand output

[License Check Output]
Extracting Bazel installation...
Starting local Bazel server (8.3.0) and connecting to it...
INFO: Invocation ID: f9b62dfd-9390-407e-9e7c-69ab0b173f4c
Computing main repo mapping: 
Computing main repo mapping: 
Computing main repo mapping: 
Computing main repo mapping: 
Loading: 
Loading: 0 packages loaded
Loading: 0 packages loaded
    currently loading: src
Analyzing: target //src:license-check (1 packages loaded, 0 targets configured)
Analyzing: target //src:license-check (1 packages loaded, 0 targets configured)

Analyzing: target //src:license-check (65 packages loaded, 9 targets configured)

Analyzing: target //src:license-check (123 packages loaded, 2288 targets configured)

Analyzing: target //src:license-check (129 packages loaded, 2435 targets configured)

Analyzing: target //src:license-check (134 packages loaded, 2484 targets configured)

INFO: Analyzed target //src:license-check (137 packages loaded, 4500 targets configured).
[12 / 13] [Prepa] Generating Dash formatted dependency file ...
INFO: Found 1 target...
Target //src:license.check.license_check up-to-date:
  bazel-bin/src/license.check.license_check
  bazel-bin/src/license.check.license_check.jar
INFO: Elapsed time: 13.735s, Critical Path: 0.40s
INFO: 13 processes: 4 disk cache hit, 9 internal.
INFO: Build completed successfully, 13 total actions
INFO: Running command line: bazel-bin/src/license.check.license_check src/formatted.txt <args omitted>
usage: org.eclipse.dash.licenses.cli.Main [-batch <int>] [-cd <url>]
       [-confidence <int>] [-ef <url>] [-excludeSources <sources>] [-help] [-lic
       <url>] [-project <shortname>] [-repo <url>] [-review] [-summary <file>]
       [-timeout <seconds>] [-token <token>]

[github-actions]

The created documentation from the pull request is available at: docu-html