metrics.json file does not support feature integration tests in module repo

### What

# Problem

The [metrics.json file](https://eclipse-score.github.io/lifecycle/main/metrics.json) file from score_lifecycle does not display the linking between feature requirements and feature integration tests.

# Context

Within lifecycle feature team we have the following setup:
* score_lifecycle repo contains [feature integration tests](https://github.com/eclipse-score/lifecycle/blob/1871923fb94e91e4ab77ffc83f826f722bcffd26/tests/integration/switch_run_target/switch_run_target.py#L21), linking to feature requirements
* score repo contains the [feature requirements](https://github.com/eclipse-score/score/blob/main/docs/features/lifecycle/requirements/index.rst) for lifecycle

This repo setup is described also in the [process documentation ](https://eclipse-score.github.io/process_description/main/general_concepts/score_building_blocks_concept.html#deployment-example).

By default, the resulting [metrics.json file](https://eclipse-score.github.io/lifecycle/main/metrics.json) from the score_lifecycle repo does not contain any feature requirements linking, but only the linking to component requirements (which are defined in the same score_lifecycle repo).

When following [dashboards_and_quality_gates documentation](https://eclipse-score.github.io/docs-as-code/main/how-to/dashboards_and_quality_gates.html#choosing-local-vs-aggregated-views) and setting `score_metrics_include_external_needs = True` & `score_metrics_requirement_types = "feat_req,comp_req,aou_req"` the metrics.json file gets polluted with all feature requirements of all modules.

I am not aware of any other settings that would support the use case.

# Expectation

score_metrics supports the use case of feature requirements and feature integration tests within different repos.
It shall be possible to generate a metrics.json file from the module repo that contains *only* the feature requirements that are relevant for the module/feature.

### Acceptance Criteria (DoD)

* score_metrics supports cross repo linking for a single feature/module to support the use case feature requirements and feature integration tests in different repos

### How

_No response_