Add app protect reconnect period directive

[galitskiy]

Proposed changes

Add app_protect_reconnect_period_seconds directive, which determines the period of time between reconnect retries of the app-protect module to the web application firewall (WAF) engine.

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto master
• I will ensure my PR is targeting the master branch and pulling from my branch from my own fork

[codecov-commenter]

Codecov Report

Merging #2360 (0f8ce5b) into master (8791d41) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2360      +/-   ##
==========================================
+ Coverage   53.65%   53.68%   +0.03%     
==========================================
  Files          48       48              
  Lines       14220    14230      +10     
==========================================
+ Hits         7630     7640      +10     
  Misses       6349     6349              
  Partials      241      241              

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	18.22% <100.00%> (+1.44%)	⬆️
internal/configs/parsing_helpers.go	69.23% <100.00%> (+0.31%)	⬆️

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[lucacome]

Left a couple of comments, mostly about clarifying the allowed values and adding them to the docs.

[jputrino]

Approved pending application of suggestion

[lucacome]

The PR looks good, but I just noticed that the pipeline is not triggered. I'm going to block the merge until we sort that out.