Adds "Host" and "X-Forwarded-For" header options

[flo-mic]

Description

This PR adds two additional headers for "Host" and "X-Forwarded-For". These headers can support on issues if you run behind a reverse proxy or if your ingress object is serving more than one url.

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 wrote unit tests for my code (if tests is required for my changes)
• I have made changes in CHANGELOG.md file

[tarampampam]

You've done a tremendous job! Thank you!

[codecov]

Codecov Report

Merging #61 (5f48587) into master (da2dc5c) will decrease coverage by 0.07%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master      #61      +/-   ##
==========================================
- Coverage   38.84%   38.76%   -0.08%     
==========================================
  Files          31       31              
  Lines        1022     1024       +2     
==========================================
  Hits          397      397              
- Misses        594      596       +2     
  Partials       31       31              

Impacted Files	Coverage Δ
internal/http/core/errorpage.go	0.00% <0.00%> (ø)
internal/tpl/properties.go	100.00% <ø> (ø)

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