`decompress_body`: Support transfer-encoding header

[wojtekmach]

[wojtekmach]

See https://github.com/elixir-mint/mint/blob/main/pages/Decompression.md

[andreyuhai]

I'd like to help with this one, once I get myself familiar with the text linked.

[thangpham7793]

Hello I'd like to help with this one unless @andreyuhai is still on it and thank you for the referenced doc.

Just to test the waters, would the changes be something like

1. Extract & combine the provided compression algorithms from transfer-encoding and content-encoding
2. Apply the algorithms in the given order (I found an example of compressing precedence rule here, so I reckon decompressing would be the reverse).

[andreyuhai]

Sorry, I said I would but then didn't really have a chance to go beyond reading it. Feel free to take it over @thangpham7793.

[wojtekmach]

Let's stick to content-encoding: ... for now.