Mock request matcher does not match camel cased HTTP header name segments

[modethirteen]

• https://github.com/modethirteen/HttpPlug/blob/main/src/Mock/MockRequestMatcher.php#L270
  • Side effect of https://github.com/modethirteen/HyperPlug/blob/main/src/Headers.php#L96
• Example: X-Deki-PageViewId vs X-Deki-Page-View-Id