introduced duplicatable V2XMessage functionality

[iwillitried]

Description

• introducing "DuplicatableMessage" interface for V2xMessage inheritors
• allows duplicating a specialised V2XMessage without importing it
• used by VariableRetransmissionApp.java when retransmitting a message

Issue(s) related to this PR

• Resolves issue: internal issue mosaic-extended#834

Affected parts of the online documentation

none

Definition of Done

Prerequisites

• You have read CONTRIBUTING.md carefully.
• You have signed the Contributor License Agreement.
• Your GitHub user id is linked with your Eclipse Account.

Required

• The title of this merge request follows the scheme type(scope): description (in the style of Conventional Commits)
• You have assigned a suitable label to this pull request (e.g., enhancement, or bugfix)
• origin/main has been merged into your Fork.
• Coding guidelines have been followed (see CONTRIBUTING.md).
• All checks on GitHub pass.
• All tests on Jenkins pass.

Requested (can be enforced by maintainers)

• New functionality is covered by unit tests or integration tests. Code coverage must not decrease.
• If a bug has been fixed, a new unit test has been written (beforehand) to prove misbehavior
• There are no new SpotBugs warnings.

Special notes to reviewer

• more code changes in mosaic-extended (same branch name)

[schwepmo]

!!! Please do not refer or link explicitly to internal resources !!!

Remove the link to the issue and only refer to it by number please. Also any internal application names should not be used explicitly

[schwepmo]

I think this is a solid solution to the problem. Nonetheless, I've added some formal concerns. Keep in mind that we try to keep the code quality of Eclipse MOSAIC at a high level, especially for newly added code.

!!! Also please remove all references (links and names) to internal code and only refer to internal issues by the issue number. !!!