Feat/Config discovery

[iGxnon]

Please briefly answer these questions:

• what problem are you trying to solve? (or if there's no problem, what's the motivation for this change?)

  This PR add a configuration discovery on operator, sidecar with an incomplete config could fetch the latest config from operator. This gives the sidecars the ability to discover each other and reconcile on a right majority.

• what changes does this pull request make?

• are there any non-obvious implications of these changes? (does it break compatibility with previous versions, etc)

[codecov]

Codecov Report

Attention: 1118 lines in your changes are missing coverage. Please review.

Comparison is base (0627722) 40.68% compared to head (65e1528) 30.17%.

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #37       +/-   ##
===========================================
- Coverage   40.68%   30.17%   -10.51%     
===========================================
  Files          21       26        +5     
  Lines        1728     2525      +797     
  Branches     1728     2525      +797     
===========================================
+ Hits          703      762       +59     
- Misses       1012     1747      +735     
- Partials       13       16        +3     

Files	Coverage Δ
operator-k8s/src/lib.rs	100.00% <ø> (ø)
sidecar/src/backup/mod.rs	80.00% <ø> (ø)
sidecar/src/backup/pv.rs	0.00% <ø> (ø)
sidecar/src/lib.rs	100.00% <ø> (ø)
operator-k8s/src/controller/cluster/v1alpha1.rs	0.00% <0.00%> (ø)
operator-k8s/src/config.rs	0.00% <0.00%> (ø)
sidecar/src/routers.rs	0.00% <0.00%> (ø)
crd-api/src/version.rs	74.35% <0.00%> (ø)
operator-k8s/src/manager/cluster.rs	79.58% <0.00%> (-0.50%)	⬇️
crd-api/src/v1alpha1/cluster.rs	92.63% <71.42%> (ø)
... and 13 more

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