bug(pom): incorrect inheritance of properties from pom fields for nested parents.

[DmitriyLewen]

Description

Trivy fills fields from pom.xml file as properties (e.g. project.version, project.parent.version, etc.)
But when there are nested parents - Trivy takes incorrect values.

Example

• Current logic - Trivy detects parent.version in parent2 (empty value) and uses this value for other pom files (parent1, scanned pom.xml).
• Correct logic - use first non empty value (1.0.0 from scanned pom.xml file).

See test example here - DmitriyLewen@3f5f697#r160365412

Discussed in #9039