Add Compressed Text Support

[monkut]

Description

Currently, in version 0.54.1, when compressed text is sent in response, zappa throws the following exception:

{'message': 
'An uncaught exception happened while servicing this request. You can investigate this with the `zappa tail` command.', 'traceback': 
['Traceback (most recent call last):\\n', 
'  File \"/var/task/handler.py\", line 596, in handler\\n
    zappa_returndict[\"body\"] = response.get_data(as_text=True)\\n', 
'  File \"/var/task/werkzeug/wrappers/response.py\", 
line 313, in get_data\\n    return rv.decode(self.charset)\\n', 
\"UnicodeDecodeError: 'utf-8' codec can't decode byte 0x8b in position 1: invalid start byte\\n\
"]}

This is intended to allow BINARY and text by making use of Content-Encoding header in the response.

When using whitenoise for caching, which provides compression, binary types may include mimetypes, "text/", "application/json":

response.mimetype.startswith("text/")
response.mimetype == "application/json"

Assuming that Content-Encoding will be set (as whitenoise apparently does) this allows compression to be applied to assets which have mimetypes "text/" and "application/json", while allowing for uncompressed "text/" and "application/json" still to be served.

About Content-Encoding:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding

Not sure if this works for all use cases, but it currently appears to work for my workcase where whitenoise is performing compression of text/json files intended for caching, while still allowing text for html.

GitHub Issues

#908

[monkut]

(Needs testcases

Looks like some test cases were prepared in the original pr:

Miserlou/Zappa#2170

[monkut]

still seems to have issues with serving *.woff files.

[Quidge]

@monkut I extended your original PR in miserlou/zappa and added some tests + formatting over in this PR.

My co has been using a fork based on that PR for some time without issue, though we don't serve .woff files. Could leverage the work + test base in that PR could be extended to include woff files possibly.

[monkut]

closing this PR as the PR below solves the same issue and is further along.

#971