[Data Mapper] Issue with generating expanded model for focused view

[KCSAbeywickrama]

Description

Generating the correct expanded DM model has been broken due to an unintended regression in wso2/vscode-extensions#897

Impact:

• When focusing on an array that is a field of a record, the dashed-line connector is not drawn.
  (There is no impact on root-level arrays.)
• Collapsing fields inside the focused array element causes the Data Mapper to crash.

Steps to Reproduce

Focused into a query that was created from an array inside a record element.

Version

1.5.3

Environment Details (with versions)

No response