Describe the bug

ProjectionExec does not preserve field metadata when generating the projected schema. I believe this will also cause it to lose dictionary information for the field.

I think fixing this will require extending PhysicalExpr with a fn field(&self, input_schema: &Schema) -> Result<Field>; or similar to replace the current logic that just constructs a new Field

To Reproduce

Create a RecordBatch with a schema with field metadata and pass it through ProjectionExec.

Expected behavior

There is potentially discussion to be had w.r.t schema-level metadata, but I would expect field-level metadata to be preserved for the fields that are projected