community[minor]: added new document loaders based on dedoc library (#24303)

### Description
This pull request added new document loaders to load documents of
various formats using [Dedoc](https://github.com/ispras/dedoc):
  - `DedocFileLoader` (determine file types automatically and parse)
  - `DedocPDFLoader` (for `PDF` and images parsing)
- `DedocAPIFileLoader` (determine file types automatically and parse
using Dedoc API without library installation)

[Dedoc](https://dedoc.readthedocs.io) is an open-source library/service
that extracts texts, tables, attached files and document structure
(e.g., titles, list items, etc.) from files of various formats. The
library is actively developed and maintained by a group of developers.

`Dedoc` supports `DOCX`, `XLSX`, `PPTX`, `EML`, `HTML`, `PDF`, images
and more.
Full list of supported formats can be found
[here](https://dedoc.readthedocs.io/en/latest/#id1).
For `PDF` documents, `Dedoc` allows to determine textual layer
correctness and split the document into paragraphs.


### Issue
This pull request extends variety of document loaders supported by
`langchain_community` allowing users to choose the most suitable option
for raw documents parsing.

### Dependencies
The PR added a new (optional) dependency `dedoc>=2.2.5` ([library
documentation](https://dedoc.readthedocs.io)) to the
`extended_testing_deps.txt`

### Twitter handle
None

### Add tests and docs
1. Test for the integration:
`libs/community/tests/integration_tests/document_loaders/test_dedoc.py`
2. Example notebook:
`docs/docs/integrations/document_loaders/dedoc.ipynb`
3. Information about the library:
`docs/docs/integrations/providers/dedoc.mdx`

### Lint and test

Done locally:

  - `make format`
  - `make lint`
  - `make integration_tests`
  - `make docs_build` (from the project root)

---------

Co-authored-by: Nasty <bogatenkova.anastasiya@mail.ru>

libs/community/tests/unit_tests/document_loaders/test_imports.py

@@ -51,6 +51,9 @@ EXPECTED_ALL = [
     "CubeSemanticLoader",
     "DataFrameLoader",
     "DatadogLogsLoader",
+    "DedocAPIFileLoader",
+    "DedocFileLoader",
+    "DedocPDFLoader",
     "PebbloSafeLoader",
     "DiffbotLoader",
     "DirectoryLoader",