What Does This Do

This PR improves the environment component to be able to check for virtual threads support.

EDIT: Support was already added in #9537 then this PR only brings few additional elements compared to the original ThreadUtils:

• A syntactic sugar helper for threadId() with current thread
• Expose the newVirtualThreadPerTaskExecutor() ExecutorServices to allow its usage from core
• Use JavaVirtualMachine.isJavaVersionAtLeast() instead of JavaVersion.getRuntimeVersion().isAtLeast() to avoid parsing version number multiple times
• Change name from ThreadUtils to the ThreadSupport as there are already two ThreadUtils classes (datadog.trace.ThreadUtils and datadog.trace.agent.test.utils.ThreadUtils)

Motivation

With the adoption of modern Java versions, we will need to check for virtual threads to avoid expensive per-thread work or memory allocation (like ThreadLocals).

Additional Notes

Contributor Checklist

• Format the title according the contribution guidelines
• Assign the type: and (comp: or inst:) labels in addition to any useful labels
• Don't use close, fix or any linking keywords when referencing an issue.
  Use solves instead, and assign the PR milestone to the issue
• Update the CODEOWNERS file on source file addition, move, or deletion
• Update the public documentation in case of new configuration flag or behavior

Jira ticket: [PROJ-IDENT]