post data to Lua only if it changes

[ElvinEfendi]

What this PR does / why we need it:

Currently we POST all dynamic data to Lua if even only one of them changes. This PR makes sure we POST only when necessary.

The PR also makes test stricter to assert request is actually being sent.

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Special notes for your reviewer:

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@5d6f8c1). Click here to learn what that means.
The diff coverage is 62.68%.

@@            Coverage Diff            @@
##             master    #4451   +/-   ##
=========================================
  Coverage          ?   58.89%           
=========================================
  Files             ?       87           
  Lines             ?     6669           
  Branches          ?        0           
=========================================
  Hits              ?     3928           
  Misses            ?     2316           
  Partials          ?      425

Impacted Files	Coverage Δ
internal/ingress/controller/controller.go	47.2% <0%> (ø)
internal/ingress/controller/nginx.go	29.22% <63.63%> (ø)

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[aledbf]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aledbf, ElvinEfendi

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• OWNERS [ElvinEfendi,aledbf]

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[ElvinEfendi]

/retest