Parts missing in the report when spec has no downstream dependencies

[JanWesterkamp-iJUG]

Specs with no downstream dependency at all show errors - only the Specification Dependency Diagram is rendered, but i.e. the Platform Dependency Diagram or the CSV list are empty.

Example configuration:

`
...

<repo.url>https://repo1.maven.org/maven2</repo.url>
<repo.filter>jakarta.::*</repo.filter>
<platform.groupId>jakarta.activation</platform.groupId>
<platform.artifactId>jakarta.activation-api</platform.artifactId>
<platform.type>jar</platform.type>
<platform.version>2.1.2</platform.version>
...
`

Log output:

`
...
[�[1;34mINFO�[m] �[1m--- �[0;32mjqassistant-maven-plugin:2.0.1:analyze�[m �[1m(default-cli)�[m @ �[36mjakarta-ee-dependencies�[0;1m ---�[m
[�[1;34mINFO�[m] Reading rules from directory '/Users/jan/git/jakarta-ee-dependencies/jqassistant'.
[�[1;34mINFO�[m] Executing analysis for 'jakarta-ee-dependencies'.
[�[1;34mINFO�[m] Will warn on violations starting from severity 'MINOR'
[�[1;34mINFO�[m] Will fail on violations starting from severity 'MAJOR'.
[�[1;34mINFO�[m] Executing group 'jakarta-ee-dependencies'
[�[1;34mINFO�[m] Applying concept 'jakarta-ee-dependencies:ArtifactDependencies' with severity: 'MINOR'.
[�[1;34mINFO�[m] Applying concept 'jakarta-ee-dependencies:ArtifactLastModifiedAsString' with severity: 'INFO'.
[�[1;34mINFO�[m] Applying concept 'jakarta-ee-dependencies:PlatformArtifact' with severity: 'MINOR'.
[�[1;34mINFO�[m] Applying concept 'jakarta-ee-dependencies:PlatformDependencyDiagram' with severity: 'MINOR'.
[�[1;34mINFO�[m] Dot version: dot - graphviz version 8.0.5 (20230430.1635)
[�[1;34mINFO�[m] Warning : cannot determine dot version
[�[1;34mINFO�[m] Rendering diagram '/Users/jan/git/jakarta-ee-dependencies/target/jqassistant/report/plantuml/jakarta-ee-dependencies_PlatformDependencyDiagram.svg'
[�[1;34mINFO�[m] Applying concept 'jakarta-ee-dependencies:PlatformDependencyVersionsByArtifact' with severity: 'MINOR'.
[�[1;34mINFO�[m] Applying concept 'jakarta-ee-dependencies:Specification' with severity: 'MINOR'.
[�[1;34mINFO�[m] Applying concept 'jakarta-ee-dependencies:SpecificationDependencyDiagram' with severity: 'MINOR'.
[�[1;34mINFO�[m] Dot version: dot - graphviz version 8.0.5 (20230430.1635)
[�[1;34mINFO�[m] Warning : cannot determine dot version
[�[1;34mINFO�[m] Rendering diagram '/Users/jan/git/jakarta-ee-dependencies/target/jqassistant/report/plantuml/jakarta-ee-dependencies_SpecificationDependencyDiagram.svg'
[�[1;34mINFO�[m] Verifying results (warn-on-severity=MINOR, fail-on-severity=MAJOR, continue-on-failure=false)
[�[1;33mWARNING�[m] --[ Concept Application Failure ]----------------------------------
[�[1;33mWARNING�[m] Concept: jakarta-ee-dependencies:PlatformDependencyDiagram
[�[1;33mWARNING�[m] Severity: MINOR
[�[1;33mWARNING�[m] Number of rows: 0
[�[1;33mWARNING�[m] Creates reports about dependencies as GraphML file and PlantUML component diagram.
[�[1;33mWARNING�[m] -------------------------------------------------------------------
[�[1;33mWARNING�[m]

[�[1;33mWARNING�[m] --[ Concept Application Failure ]----------------------------------
[�[1;33mWARNING�[m] Concept: jakarta-ee-dependencies:PlatformDependencyVersionsByArtifact
[�[1;33mWARNING�[m] Severity: MINOR
[�[1;33mWARNING�[m] Number of rows: 0
[�[1;33mWARNING�[m] Creates a CSV report about dependency versions.
[�[1;33mWARNING�[m] -------------------------------------------------------------------
[�[1;33mWARNING�[m]

[�[1;34mINFO�[m] �[1m------------------------------------------------------------------------�[m
[�[1;34mINFO�[m] �[1;32mBUILD SUCCESS�[m
[�[1;34mINFO�[m] �[1m------------------------------------------------------------------------�[m
[�[1;34mINFO�[m] Total time: 09:35 min
[�[1;34mINFO�[m] Finished at: 2023-05-28T14:23:50+02:00
[�[1;34mINFO�[m] �[1m------------------------------------------------------------------------�[m
[�[1;34mINFO�[m] Closing connection to store 'file:/Users/jan/git/jakarta-ee-dependencies/target/jqassistant/store/'.
`

[JanWesterkamp-iJUG]

Another example configuration with a POM type artifact:

`
...

<repo.url>https://repo1.maven.org/maven2</repo.url>
<repo.filter>jakarta.::*</repo.filter>
<platform.groupId>jakarta.batch</platform.groupId>
<platform.artifactId>batch-api-parent</platform.artifactId>
<platform.type>pom</platform.type>
<platform.version>2.1.1</platform.version>
...
`