`quarkus.hibernate-orm.database.generation` values should be enumerated

[fbricon]

Currently quarkus.hibernate-orm.database.generation provides no completion for its possible values. We should see none, create, drop-and-create, drop, update.

You can see an example in https://github.com/fbricon/quarkus-spread-poll/blob/master/src/main/resources/application.properties#L19

[angelozerr]

To fix this issue, we should declare on quarkus-ls an hints for this property like https://github.com/eclipse/lsp4mp/blob/ab86a54e2be98c20ada1664ce910a015779c6b4d/microprofile.jdt/org.eclipse.lsp4mp.jdt.core/static-properties/mp-opentracing-metadata.json#L31

[angelozerr]

Like Spring Boot does https://github.com/spring-projects/spring-boot/blob/a8705d19e59c6ab0a8555c079e59995aad395210/spring-boot-project/spring-boot-autoconfigure/src/main/resources/META-INF/additional-spring-configuration-metadata.json#L1871

[angelozerr]

This issue should be very easy to do.