Parquet > Add support for the rest of the Parquet encodings

[avalerio-tkd]

• Currently only PLAIN encoding is supported. This is the default encoding when use_dictionary is disabled, so in practice PLAIN will be used except when an explicit overwrite happens.
• RLE_DICTIONARY will never be supported because by definition the values are not present (kept separate in the dictionary) so a per-block encryption will always be triggered in these cases.