Enable tomcat monitoring and generalize prometheus endpoint exposure

[antoinebhs]

Please check if the PR fulfills these requirements

• The commit message follows our guidelines

What kind of change does this PR introduce?

• Enable tomcat monitoring in our microservices.
• Add the actuator/prometheus endpoint by default

Other informations
Will be release with powsybl/powsybl-ws-dependencies#37

[Tristan-WorkGH]

As this config is used not only by GridSuite, have you checked if adding "prometheus" in exposures and the dependencies micrometer-registry-prometheus or spring-boot-actuator aren't present spring-boot don't fail somewhere?

[antoinebhs]

As this config is used not only by GridSuite, have you checked if adding "prometheus" in exposures and the dependencies micrometer-registry-prometheus or spring-boot-actuator aren't present spring-boot don't fail somewhere?

I verified that if the dependency micrometer-registry-prometheus is not added, the endpoint actuator/prometheus is not created as expected. There is no error.