Allow to get parent of BaseNode
merged branch Strate/strate/improvement/get-parent-of-node (PR #8302)

This PR was submitted for the 2.3 branch but it was merged into the master branch instead (closes #8302).

Discussion
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[Config] Allow to get parent of BaseNode

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no (improvement)
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Like an ArrayNode have method `getChildren`, I might to be good idea for having method `getParent` of all nodes.

Commits
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a9a7ecc [Config] Allow to get parent of BaseNode