Process Log Format String for Logger Compatibility

[ozangoktan]

ResponseHeader Placeholder: Improved compatibility with logger implementations(Serilog at the least), replacing bracketed part with a numeric suffix before passing the format string through to the logger.

[codecov[bot]]

Codecov Report

Merging #137 (3b97fb5) into master (dd53a1e) will increase coverage by 0.16%. The diff coverage is 100.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #137 +/- ## ========================================== + Coverage 77.58% 77.74% +0.16% ========================================== Files 9 9 Lines 687 692 +5 Branches 41 41 ========================================== + Hits 533 538 +5 Misses 127 127 Partials 27 27 ``` | [Files](https://app.codecov.io/gh/cognitedata/oryx/pull/137?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cognitedata) | Coverage Δ | | |---|---|---| | [src/HttpHandler/Logging.fs](https://app.codecov.io/gh/cognitedata/oryx/pull/137?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cognitedata#diff-c3JjL0h0dHBIYW5kbGVyL0xvZ2dpbmcuZnM=) | `95.12% <100.00%> (+0.31%)` | :arrow_up: |