Make ColumnPath immutable

[findepi]

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• My PR addresses the following Parquet Jira issues and references
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[findepi]

cc @raunaqmorarka

• My PR addresses the following Parquet Jira issues and references
  them in the PR title.

not yet. I will create one if needed

[raunaqmorarka]

I think it would also help to have a boolean equals(String[] path) method so that we can make path equality checks without incurring an unnecessary array copy.

[findepi]

I know it could be useful for Parquet users such as Trino, but was hesitant to add this as not directly related to immutability. Since toArray became copying, i added toList which avoids copy. Maybe this new method also satisfies those needs and we don't need yet another one?

[raunaqmorarka]

ya, i think that new method will help

[raunaqmorarka]

ya, i think that new method will help