Lenient header matching

[honnix]

Hey, I just made a Pull Request!

Description

Matching headers as substring to handle cases we don't need to match full header name.

Motivation and Context

There are cases we cannot match full header name, so instead we check by substring match.

Have you tested this? If so, how?

I modified unit test to cover this change.

Checklist for PR author(s)

• Changes are covered by unit test
• All tests pass
• Code coverage check passes
• Error handling is tested
• Errors are handled at the appropriate layer
• Errors that cannot be handled where they occur are propagated
• (optional) Changes are covered by system test
• Relevant documentation updated
• This PR has NO breaking change to public API
• This PR has breaking change to public API and it is documented

Checklist for PR reviewer(s)

• This PR has been incorporated in release note for the coming version
• Risky changes introduced by this PR have been all considered

[codecov]

Codecov Report

Merging #1091 (836a2b7) into master (0575e5b) will increase coverage by 0.04%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             master    #1091      +/-   ##
============================================
+ Coverage     92.32%   92.37%   +0.04%     
  Complexity     2150     2150              
============================================
  Files           200      200              
  Lines          8323     8325       +2     
  Branches        503      503              
============================================
+ Hits           7684     7690       +6     
+ Misses          525      520       -5     
- Partials        114      115       +1