Allow merging arrays in omnibus configuration - Take 2

What does this MR do and why?

Describe in detail what your merge request does and why.

Allow merging arrays in omnibus configuration.

See this conversation for context on how this change will be helpful: !1207 (comment 1461998540)

The original MR was reverted due to #717 (closed)

This MR fixes the issue by adding support for merging arrays even for multiline omnibus configurations.

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