Unable to parse Document result in Python

using textract-trp 0.1.3

When parsing "get_document_analysis" response the following output is generated:

```
Traceback (most recent call last):
File "G:\dev\OCR\main.py", line 17, in
result = (textract.receive_document_result('52c4a450c667a18d89f4e26a1cf4b56859ad239f1a63279bec8f60458ae2284e'))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "G:\dev\OCR\textract.py", line 62, in receive_document_result
return Document(response)
^^^^^^^^^^^^^^^^^^
File "G:\dev\OCR\venv\Lib\site-packages\trp\__init__.py", line 633, in __init__
self._parse()
File "G:\dev\OCR\venv\Lib\site-packages\trp\__init__.py", line 667, in _parse
page = Page(documentPage["Blocks"], self._blockMap)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "G:\dev\OCR\venv\Lib\site-packages\trp\__init__.py", line 516, in __init__
self._parse(blockMap)
File "G:\dev\OCR\venv\Lib\site-packages\trp\__init__.py", line 530, in _parse
l = Line(item, blockMap)
^^^^^^^^^^^^^^^^^^^^
File "G:\dev\OCR\venv\Lib\site-packages\trp\__init__.py", line 142, in __init__
if(blockMap[cid]["BlockType"] == "WORD"):
~~~~~~~~^^^^^
KeyError: '9e2f5e38-f865-4b79-a37b-ac8ed7a19f02'
```

Start by reproducing the get_document_analysis response and inspect trp/__init__.py around Document._parse, Page._parse, and Line.__init__, as shown in the traceback. Done means the response parses without the reported KeyError and the affected block-reference case is covered by a test.

Scritto dal modello di indicizzazione a partire dal testo della issue.