Added rewriteResponseBody as a middleware

[RodoMa92]

Description
This add the requested feature #15328 to the best of my abilites, but it should be double checked for eventual mistakes. I've based this comparing the install procedure for kubernetes here and the already present rewrite headers in this repo and merged the two.

⚒️ Fixes #15328

⚙️ Type of change

• ⚙️ Feature/App addition
• 🪛 Bugfix
• ⚠️ Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 🔃 Refactor of current code

✔️ Checklist:

• ⚖️ My code follows the style guidelines of this project
• 👀 I have performed a self-review of my own code
• #️⃣ I have commented my code, particularly in hard-to-understand areas
• 📄 I have made corresponding changes to the documentation
• ⚠️ My changes generate no new warnings
• 🧪 I have added tests to this description that prove my fix is effective or that my feature works
• ⬆️ I increased versions for any altered app according to semantic versioning

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[PrivatePuffin]

missing version increase, missing values.yaml example, missing GUI component for SCALE.

[PrivatePuffin]

Also is missing the actual plugin.
But i'm not in favor anyway, as this plugin isn't actively maintained.

[RodoMa92]

There is also this fork available, does this might be a better fit? https://github.com/dirtycajunrice/subfilter

I'll keep looking around otherwise.

[RodoMa92]

Yeah, even less updated, now that I look at it. I'll keep searching then.

[RodoMa92]

Yeah, sadly I can't find any replacement for it. I might have a better look later.