fix: Close Cube Store on process.exit

[ovr]

Hello!

There is an issue Node.js when it doesn't kill child process: nodejs/node#13538. In this PR I did a workaround for it. Probably it's a default behaviour:

Still sounds like the wrong expectation to me. When SIGTERM terminates the parent, children get reparented to the grandparent. That's not node-specific, it's traditional UNIX behavior.

Thanks

[codecov]

Codecov Report

Merging #3082 (2d8ce8e) into master (815da47) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3082   +/-   ##
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  Coverage   59.59%   59.59%           
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  Files         124      124           
  Lines        9497     9497           
  Branches     2109     2109           
=======================================
  Hits         5660     5660           
  Misses       3551     3551           
  Partials      286      286           

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