M3 observability

See merge request !33

M3 data initialization

See merge request !34

# Conflicts:
#   application/module-language-school/src/main/java/org/fuseri/modulelanguageschool/course/Course.java

M2 fix exercise

See merge request !32

M2 fix certificate

See merge request !36

M2 fix language school

See merge request !35

M2

See merge request !31

# Conflicts:
#	application/model/src/main/java/org/fuseri/model/dto/user/UserDto.java
#	application/module-certificate/src/test/java/org/fuseri/modulecertificate/CertificateControllerTests.java
#	application/module-certificate/src/test/java/org/fuseri/modulecertificate/CertificateFacadeTests.java
#	application/module-certificate/src/test/java/org/fuseri/modulecertificate/CertificateMapperTests.java
#	application/module-certificate/src/test/java/org/fuseri/modulecertificate/CertificateServiceTests.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseFacade.java
#	application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/user/UserControllerTest.java