replace local jwt with library version

- update ConfigurationController to handle hlaeja jwt instead of jwtService
- update MeasurementController to handle hlaeja jwt instead of jwtService
- add dependency for hlaeja jwt
- remove dependencies for jjwt
- remove JwtService.kt
- remove PublicKeyProvider.kt
- remove jwt key property explanation from additional-spring-configuration-metadata.json

.gitignore

@@ -39,5 +39,5 @@ out/
 ### Kotlin ###
 .kotlin
 
-### cert ###
-cert/
+#### Hlæja ###
+/cert/