Harmonized Versions with Spring Boot Dependencies v2.5.5

Created by: TheSasch

• Sorted pom with sortpom plugin to have the same structure as https://maven.apache.org/developers/conventions/code.html#pom-code-convention
• Set each version as a property to change it easier. Same style as spring-boot dependencies bom
• Removed some unused dependencies
• Harmonized Hamcrest import to only use one Hamcrest dependency tree