Add new SmallRyeOpenAPI public builder API

[MikeEdgar]

Closes #1762

[Azquelt]

I'll have a read through this, but for reference the place where we call smallrye OpenAPI in OpenLiberty is here: https://github.com/OpenLiberty/open-liberty/blob/a0f4167ee6dfad2d80a420d32ea410d4df239542/dev/io.openliberty.microprofile.openapi.2.0.internal/src/io/openliberty/microprofile/openapi20/internal/ApplicationProcessor.java#L301

[sonarqubecloud[bot]]

Quality Gate passed

Issues
16 New issues
0 Accepted issues

Measures
0 Security Hotspots
87.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud