Get bot building and running on Java JDK 17 (LTS).

TODO:

• Re-enable all Maven unit tests.
• Re-enable all Gradle unit tests.
• Maven coverage @ 80% target (excl. Powermock tests).
• Gradle coverage @ 80% target (excl. Powermock tests).
• Complete all JDK 17 related FIXMEs and TODOs in code.
• Sonar fixes.
• Remove defunct itBit exchange adapter - Paxos killed off the itBit REST API on 26 April 2023: https://api.itbit.com/doc
• Fix missing "org.springframework.cloud.context.restart.RestartEndpoint' issue.
• Live exchange test with Maven bot distro.
• Live exchange test with Gradle bot distro.
• PR.
• Release.