Remove Essentials and Groupmamager-specific dependencies
Revert "Remove Essentials and Groupmamager-specific dependencies"

This reverts commit f57100547f4bcd45b7eb7c7a5c62f66cbe05a87a.

	modified:   pom.xml
	modified:   src/main/java/io/github/likcoras/buyable/PrefixCommandExecutor.java
	modified:   src/main/java/io/github/likcoras/buyable/buyablePrefixes.java
	modified:   src/main/resources/plugin.yml
Organized/fixed code and removed useless code
Removed dependencies to essentials and groupmanager
Set up vault dependency