Propagate datanode version through node service

[todvora]

Make exact datanode version available through node service pings. The version should be then used to verify that datanodes and graylog servers run the same compatible version.

Requested in #18783
Fixes #19680

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (non-breaking change)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.

[gally47]

Can we please add it to the datanode details page too

[todvora]

@gally47 Thanks, good point, added:

[moesterheld]

found one more minor point, otherwise everything looks good:

for completeness, I would also propagate the version already in the registerServer method of the NodePingPeriodical

[gally47]

Frontend LGTM. Thanks for working on this @todvora.

[moesterheld]

lgtm. thank you