(Created as a result of WT-10270)

The following cell unpacking calls are made from the RTS subsystem:

• wt_page_cell_data_ref_kv
• wt_cell_rle
• wt_cell_type_raw
• wt_cell_unpack_addr
• wt_cell_unpack_kv

There should be one place in WiredTiger that decodes on-disk cell information and returns the desired information. Having RTS directly/explicitly decode cells should not be necessary.