Add namespaces (packages) to packageInfo

[JimSuplizio]

For the Spring people on this PR: I'm opportunistically fixing sdk/spring/spring-cloud-azure-starter-appconfiguration-config/pom.xml which has been causing a build warning because of the duplicate org.apache.maven.plugins:maven-jar-plugin definition.

The namespaces (packages) are added to the packageInfo json files prior to being processed by MSDocs. The problems with this are as follows:

1. This doesn't happen until the Docs.MS Release task at release time, which is a bit late if there's a problem.
2. The process that pulls namespaces does so from the javadoc and instead of using the one that's built, it downloads the javadoc jar, effectively making a needless network call.

The solution is to add the namespaces to the packageInfo files earlier in the process. Because I'm using the staged artifacts, the place to put this is just after the artifacts have been staged. The Fetch-Namespaces-From-Javadoc function in Docs-Toc.ps1 was updated to take the location of the javadoc jar. If the location was set, it'll use that instead of trying to download. This fixes #2 above.

Get the namespaces to update the packageInfo during the Build job, just after artifacts are copied to staging. This fixes #1. The reason for doing this here is that there were issues with people not having skipPublishDocMs set, meaning that it's expecting to produce docs, but the library was creating an empty javadoc jar with just the README so no namespaces could be determined.

Testing was done against the java - core - ci, which has libraries that publish docs, and java - template - ci whose libraries do not publish docs.

This fixes the Java part of Azure/azure-sdk-tools#7990

Note: I'm setting skipPublishDocMs and skipPublishDocGithubIo to true for com.azure.spring:spring-cloud-azure-appconfiguration-config-web because its POM file is producing an empty javadoc jar so we can't determine namespaces. This failure is known and needs to be fixed.

Q) Why use the Javadoc Jar instead of the actual library's jar?
A) The maven-javadoc-plugin definition has exclusions, things we don't want in docs. The main plugin definition, defined in azure-client-sdk-parent, has common exclusions with additional exclusions able to be defined in a library's individual pom file. This means that these classes are not part of the documentation and the exclusion is done at build time for the javadoc jar file. The library's jar would still have these classes meaning we'd have to duplicate the exclusions in some manner which would be janky, at best.

[azure-sdk]

API change check

API changes are not detected in this pull request.

[weshaggard]

I suggest move the filtering into the script.

[JimSuplizio]

This is already past the point where all of my changes are being tested and core is having a random failure. Since my change to sdk/spring/spring-cloud-azure-appconfiguration-config/pom.xml fixes a version SNAFU affecting every pipeline I'm going to override check-enforcer and merge