Implementation of the http2 observer and decoder.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 58.44156% with 224 lines in your changes missing coverage. Please review.

Project coverage is 63.8%. Comparing base (1b1d4b9) to head (66220f1).

:exclamation: Current head 66220f1 differs from pull request most recent head 3f782e1

Please upload reports for the commit 3f782e1 to get more accurate results.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1516 +/- ## ======================================== + Coverage 63.0% 63.8% +0.7% ======================================== Files 214 153 -61 Lines 51857 36006 -15851 Branches 5986 5947 -39 ======================================== - Hits 32681 22976 -9705 + Misses 16966 10439 -6527 - Partials 2210 2591 +381 ``` | [Flag](https://app.codecov.io/gh/skupperproject/skupper-router/pull/1516/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=skupperproject) | Coverage Δ | | |---|---|---| | [pysystemtests](https://app.codecov.io/gh/skupperproject/skupper-router/pull/1516/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=skupperproject) | `?` | | | [systemtests](https://app.codecov.io/gh/skupperproject/skupper-router/pull/1516/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=skupperproject) | `63.8% <58.4%> (+7.6%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=skupperproject#carryforward-flags-in-the-pull-request-comment) to find out more. | [Components](https://app.codecov.io/gh/skupperproject/skupper-router/pull/1516/components?src=pr&el=components&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=skupperproject) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/skupperproject/skupper-router/pull/1516/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=skupperproject) | `63.8% <58.4%> (+0.7%)` | :arrow_up: | | [systemtests](https://app.codecov.io/gh/skupperproject/skupper-router/pull/1516/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=skupperproject) | `63.8% <58.4%> (+7.6%)` | :arrow_up: |