Experiments with running ES with the entitlements agent enabled

[prdoyle]

Not looking to merge this; just making a PR for reviewability.

The headlines:

The bridge module now has an spi package

The bridge module has become a useful "leaf module" that everything can depend on to interoperate:

• The api package is what instrumented code calls to perform the checks
  • Needed by the agent and the runtime
• The spi package is what the agent uses to load its impl module
  • Needed by the agent and by org.elasticsearch.base, which needs access to any interfaces loaded by the embedded provider Gradle plugin

The bridge module itself has no dependencies.

ServerCLI changes

SystemJvmOptions.java now has a stanza for the entitlement command line options. It uses Files.newDirectoryStream to locate the jar file within the working directory. (We could probably calculate this statically instead if that's preferable, but the obstacle is that the jar file name contains the version number, like -9.0.0, which I wasn't sure how to access programmatically.)

Hacks

• I had to comment out LogManager.getLogger in ModuleQualifiedExportsService

Refactoring

You might want to review this commit separately. It's a simpler, more uniform way to knit together groups of zero or more options.

[prdoyle]

Yeah this guy again.

[prdoyle]

Ok I'm getting unit test failures because the jar file doens't exist at the expected path. I guess looking at the filesystem to find the jars wasn't so smart after all.

java.nio.file.NoSuchFileException: ./lib/tools/entitlement-agent
	at __randomizedtesting.SeedInfo.seed([B9C9111FE4D76380:15830EB4CCA5F44C]:0)
	at java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:92)
	at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:106)
	at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111)
	at java.base/sun.nio.fs.UnixFileSystemProvider.newDirectoryStream(UnixFileSystemProvider.java:461)
	at java.base/java.nio.file.Files.newDirectoryStream(Files.java:549)
	at org.elasticsearch.server.cli.SystemJvmOptions.findEntitlementComponent(SystemJvmOptions.java:156)
	at org.elasticsearch.server.cli.SystemJvmOptions.maybeEntitlementAgent(SystemJvmOptions.java:146)
	at org.elasticsearch.server.cli.SystemJvmOptions.systemJvmOptions(SystemJvmOptions.java:76)
	at org.elasticsearch.server.cli.JvmOptionsParserTests.testNodeProcessorsActiveCount(JvmOptionsParserTests.java:356)