fix(v2x): API Change in V2xMessage getPayLoad -> getPayload

[schwepmo]

Description

• This PR introduces an API change to correct spelling
• the method V2xMessage#getPayLoad is now correctly spelled as V2xMessage#getPayload
• all occurrences using this API were adjusted accordingly

BREAKING CHANGE: Applications using the V2xMessage#getPayLoad()-method will have to adjust to the corrected spelling of V2xMessage#getPayload()

Issue(s) related to this PR

• Resolves internal issue 771

Affected parts of the online documentation

• None, if I checked properly

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

[kschrab]

Have you looked into the bundled scenarios if any of them refers to getPayLoad in the output_config.xml?