Archetype: Feature parity with 3.x + renaming from nima to se

[tvallin]

fix #7268 and #7243

[barchetta]

When I try to generate a Quickstart SE project (SE -> quickstart). I get an error:

 error: Invocation error: Unresolved variable: db

[barchetta]

Using Custom SE and adding Health support and built-in checks, the README says to do: curl -X GET http://localhost:PORT/health/

• I had to use the URL http://localhost:8080/observe/health
• Health in SE now returns no content (204), in 3.x it returned content and a 200. If this is indeed how health in SE is to work, the README should mention that (because it feels like a bug when you run curl and nothing appears to happen)

[barchetta]

Observed with SE quickstart:

• READMEs should say "JDK21" not "JDK20"
• README: "Exercise the application" has curl -X GET http://localhost:8080/simple-greet example shown twice
• README: Line 113 and 148 consists of 32 blank spaces

Observed with database-se

• It is configured with tracing (not so in 3.x) and zipkin2.reporter throws an exception at startup
• curl -X GET http://localhost:8080/pokemon returns "Endpoint not found"

Observed with database-mp using Hibernate

• Compile warning: [WARNING] unknown enum constant org.osgi.annotation.bundle.Requirement.Resolution.OPTIONAL
• Compile error:

[ERROR] Failed to execute goal org.hibernate.orm.tooling:hibernate-enhance-maven-plugin:6.1.7.Final:enhance (default) on project database-mp: Unable to enhance class: ObjectFactory.class: Failed to enhance class io.helidon.archetypes.tests.jaxb.ObjectFactory: Java 21 (65) is not supported by the current version of Byte Buddy which officially supports Java 20 (64) - update Byte Buddy or set net.bytebuddy.experimental as a VM property -> [Help 1]

Observed with database-mp using EclipseLink:

• Same compile warning as with Hibernate
• Endpoints work!

[barchetta]

Looks good enough to merge. I've created a followup issue: #7446