feat (provider/groq): reasoning format support

[lgrammel]

Fixes #5233

Summary

• update groq models
• support groq reasoning format option
• omit empty groq text deltas

Tasks

• update groq models (settings)
• update groq models (docs)
• groq reasoning section (docs)
• implement groq reasoning
  • option
  • option test
  • generate
  • generate test
  • stream
  • stream test
  • test out defaults - would need to be model specific, not adding
  • extract provider option parsing
• groq reasoning example
  • generate
  • stream
• changeset