ADPT-156: Add manual priority usability to adapter

[gitgoodjhe]

---

For the submitter:

• I updated the documentation and will supply links to the specific files
• I did not update the documentation
• I included a link to the SonarCloud branch analysis
• I added a description of changes on the current release notes
• I did not update the current release notes
• I put the ticket in review

Verified by the reviewer:

• Commit message format → ADPT-XXX: Your commit message.
• Submitter's update to documentation is sufficient
• SonarCloud analysis meets our standards
• Update of the current release notes reflects changes
• PR fulfills the ticket
• Edge cases and unwanted side effects are tested
• Readability

[holgerhagen]

Do we need a test for the default initialization to -1?

And maybe we should have a second look at the names. Is it really correct that we do have such many "ReferencedTask"s?

[gitgoodjhe]

Updated doc: https://taskana.atlassian.net/wiki/spaces/TAS/pages/881164289/Camunda+BPM+Connector