Fix encoding of edge cases of escape sequences

[y86]

Fix the following error when encoding weirdly escaped strings, such as "/\\\\\\\\\\\\/windows%2fwin.ini%23vt/test":

gen_event handler terminating (CaseClauseError): no case clause matching: :quoted_and_escaped

Logfmt.Encoder.deduce_string_style/2 (logfmt)(lib/logfmt/encoder.ex:79)
Logfmt.Encoder.encode_value/1 (logfmt)(lib/logfmt/encoder.ex:42)
Logfmt.Encoder.encode_pair/1 (logfmt)(lib/logfmt/encoder.ex:57)
Enum."-map/2-lists^map/1-0-"/2 (elixir)(lib/enum.ex:1294)