schema: max_length must be 1 or greater (never 0)

Implement max/exclude choices options in schema

Enhance compose

Remove empty values from generated choices

Enhance compose

Use new metadata on rows schema for CSV/txt output

Fix total_read bytes on pgimport when rows are skipped

Fix USING when access_method is None

[postgres] Add option to COPY using FORMAT BINARY

Force provided encoding in rows schema

Fix library API

Convert Groups to TextObjects after grouping Tesseract objects

Add helper functions to PDF module