Do not wait informer initialization to read configuration

[aledbf]

What this PR does / why we need it:

Read configuration configmap while the controller is being initialized. This avoids passing health checks without having applied the configuration defined in the configmap.

Which issue this PR fixes:

fixes #2629

[antoineco]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

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

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• OWNERS [aledbf]

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[codecov-io]

Codecov Report

Merging #2658 into master will increase coverage by 0.08%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #2658      +/-   ##
==========================================
+ Coverage   40.75%   40.84%   +0.08%     
==========================================
  Files          72       72              
  Lines        5069     5073       +4     
==========================================
+ Hits         2066     2072       +6     
+ Misses       2721     2718       -3     
- Partials      282      283       +1

Impacted Files	Coverage Δ
internal/ingress/controller/store/store.go	60.18% <100%> (+1.12%)	⬆️

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