Dedoc

* Add bbox annotations in `PdfTabbyReader`.
* Add bbox annotations for words in `PdfTxtlayerReader`.
* Add an option `plain_text` to the `return_format` parameter.
* Reduce size of the dedoc base image, move dockerfiles to the [separate repository](https://github.com/ispras/dedockerfiles).
* Refactor script for tesseract benchmarking.
* Make fixed dedoc dependencies as ranges.
* Add table cell properties in `PdfTabbyReader`.

* Rename exceptions classes.
* Update style tests.
* Change `ConfidenceAnnotation` value range to `[0, 1]`.
* Add bbox annotations for words in `PdfImageReader`.

* Add ConfidenceAnnotation annotation for PdfImageReader.
* Remove version parameter from metadata extractors, structure constructors and parsed document methods.
* Add version file and version resolving for the library.
* Add recursive handling of attachments.
* Add parameter for saving attachments in a custom directory.
* Remove dedoc threaded manager.
* Improve PdfAutoReader.
* Add temporary file name to DocumentMetadata.

* Fix bug for diplomas with `insert_table=true`.
* Fix logging in PDF slicing.
* Make PdfAutoReader faster.
* Update bold classifier.
* Tests Refactoring.
* Fix bug in models downloading inside docker container.

* Fixed bug with `AttachAnnotation` in docx: its value is equal attachment uid instead of file name.

* Publication of the first version of dedoc library

version_2021_01_25