Support new directive for dos: app_protect_dos_arb_fqdn

[pasmant]

Added - app-protect-dos-arb-fqdn - new option in Config Map

Arbitrator FQDN has one argument which is the FQDN/IP.
The argument is the FQDN to the desired Arbitrator.

Examples for ConfigMap data:

FQDN:

data:
  app-protect-dos-arb-fqdn svc-appprotect-dos-arb.arb.svc.cluster.local;

IP address:

data:
  app-protect-dos-arb-fqdn 192.168.1.10;

[codecov-commenter]

Codecov Report

Merging #2745 (730bfbc) into main (fea43bc) will decrease coverage by 0.01%.
The diff coverage is 16.66%.

❗ Current head 730bfbc differs from pull request most recent head 7f2514f. Consider uploading reports for the commit 7f2514f to get more accurate results

@@            Coverage Diff             @@
##             main    #2745      +/-   ##
==========================================
- Coverage   52.32%   52.31%   -0.02%     
==========================================
  Files          58       58              
  Lines       15959    15965       +6     
==========================================
+ Hits         8351     8352       +1     
- Misses       7330     7335       +5     
  Partials      278      278              

Impacted Files	Coverage Δ
internal/configs/config_params.go	76.74% <ø> (ø)
internal/configs/version1/config.go	0.00% <ø> (ø)
internal/configs/configmaps.go	18.20% <16.66%> (-0.02%)	⬇️

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[lucacome]

@pasmant left some comments. Would also mind adding a description for the changes in this PR? Thanks!