Access log formatters

• Formatter extension for printing CEL expressions (proto)
  • extensions.formatter.cel.v3.Cel
• Formatter extension for reading file contents (proto)
  • extensions.formatter.file_content.v3.FileContent
• Formatter extension for printing values from generic secrets (proto)
  • extensions.formatter.generic_secret.v3.GenericSecret
• Formatter extension for printing various types of metadata (proto)
  • extensions.formatter.metadata.v3.Metadata
• Formatter extension for printing request without query string (proto)
  • extensions.formatter.req_without_query.v3.ReqWithoutQuery