MissingJavaDoc checker to support * for ignoring group of files

[saratvemulapalli]

Is your feature request related to a problem? Please describe.
MissingJavaDoc gradle task doesnt support ignoring group of files.
For example: Generated code dont follow our standards and have to be ignored.
Coming from PR: #6960 (comment)

Describe the solution you'd like
Add support to ignore multiple files with *

Eg:
Before:

javadocMissingIgnore = [
    "org.opensearch.extensions.proto.ExtensionRequestProto",
    "org.opensearch.extensions.proto.ExtensionRequestProto.ExtensionRequestOrBuilder",
    "org.opensearch.extensions.proto"
  ]

After:

javadocMissingIgnore = [
    "org.opensearch.extensions.proto.*"
  ]

[dbwiddis]

OpenSearch might want to consider using Checkstyle for javadocs as we do on SDK. I know Checkstyle was removed for style, but it's got an extremely powerful feature set for configuring javadoc checks and if it's limited to those, I think it could replace our existing missing javadoc check, which is an unmaintained, copied-from-Lucene/Solr hack that I don't think anyone should spend time updating.

See also #4541

[austintlee]

I had a quick look and this looks like a fairly straightforward thing to support (a few lines of code). But is it "safe" to support this? It seems to me that perhaps this was by design. Supporting '*' could lead to misuse/abuse.

[dblock]

+1 to what @austintlee says, but also maybe it's NBD and a fine workaround to mark generated code as such

Another option is to generate code that complies with our checkstyle.

[austintlee]

@saratvemulapalli I created a PR to suggest a possible way to make this work using an allowlist. One question I have is around where that allowlist should be placed. Please, take a look. Thanks!

[austintlee]

If we are OK with this approach in general, I can also add some unit tests for MissingDoclet. At the moment, this whole package (org.opensearch.missingdoclet) has no unit tests.

[austintlee]

I am proceeding with an approach that allows only generated classes annotated with '@javax.annotation.Generated' to be ignored.

Of course, all other exceptions will still need to be added to build.gradle manually.