JsonNodeValueResolver.toMap() should resolve the value of the Map.Entry in entrySet()

[DavidWei252]

The current entrySet() implementation of the Map inside the JsonNodeValueResolver.toMap() function didn't resolve the value of the entry. (source)

For example:
With input { "array": [ {"foo":"bar"},{"foo":"biz"} ] } and template {{ join this.array ", " }}

The current implementation will output {foo="bar"},{foo="biz"}
Instead we want the output become {foo=bar},{foo=biz}

Task:
Update the current entrySet() implementation of the Map inside the JsonNodeValueResolver.toMap() function to resolve the entry value.

[carusology]

Candidate in #965.