use richtext codec for content type

[TomTriple]

Commit due to #2416

• use RichTextCodec for ContentType header
• accept multiple parameters in ContentType (but only keep boundary and charset around after parsing)
• accept quoted version for parameter values

[codecov-commenter]

Codecov Report

Patch coverage: 95.16% and project coverage change: +0.52% 🎉

Comparison is base (8780eb9) 64.21% compared to head (b033266) 64.74%.

❗ Current head b033266 differs from pull request most recent head 592fed8. Consider uploading reports for the commit 592fed8 to get more accurate results

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Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2455      +/-   ##
==========================================
+ Coverage   64.21%   64.74%   +0.52%     
==========================================
  Files         136      136              
  Lines        7118     7148      +30     
  Branches     1302     1298       -4     
==========================================
+ Hits         4571     4628      +57     
+ Misses       2547     2520      -27     

Files Changed	Coverage Δ
zio-http/src/main/scala/zio/http/Header.scala	63.52% <94.73%> (+2.15%)	⬆️
zio-http/src/main/scala/zio/http/MediaType.scala	96.55% <100.00%> (+0.12%)	⬆️
.../src/main/scala/zio/http/codec/RichTextCodec.scala	88.58% <100.00%> (+4.52%)	⬆️

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