feat(controllers): Implement the TerraformRun controller

[corrieriluca]

Fixes #165

Checklist

• TerraformRun controller fully functional
• Support for a default maxRetries value in the config
• Update documentation
• Update Helm chart and manifests
• [WIP in PR feat(tfrun): Add cleanup of past TerraformRuns #168] Implement a TerraformRun "garbage collector" (i.e. delete after a certain time/number)

[codecov-commenter]

Codecov Report

Merging #167 (4d70a9d) into main (c0abbca) will increase coverage by 1.46%.
The diff coverage is 78.12%.

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@@            Coverage Diff             @@
##             main     #167      +/-   ##
==========================================
+ Coverage   69.04%   70.50%   +1.46%     
==========================================
  Files          23       28       +5     
  Lines        1586     1926     +340     
==========================================
+ Hits         1095     1358     +263     
- Misses        425      492      +67     
- Partials       66       76      +10     

Files	Coverage Δ
api/v1alpha1/common.go	100.00% <ø> (ø)
internal/annotations/annotations.go	100.00% <ø> (ø)
internal/controllers/terraformlayer/conditions.go	62.31% <ø> (-2.79%)	⬇️
internal/controllers/terraformlayer/controller.go	38.80% <100.00%> (-8.82%)	⬇️
internal/controllers/terraformlayer/run.go	100.00% <100.00%> (ø)
internal/controllers/terraformpullrequest/layer.go	84.00% <100.00%> (+0.43%)	⬆️
internal/lock/lock.go	93.02% <100.00%> (+1.84%)	⬆️
internal/burrito/config/config.go	48.75% <0.00%> (-0.62%)	⬇️
internal/controllers/terraformlayer/states.go	77.41% <73.33%> (+9.28%)	⬆️
internal/controllers/terraformrun/pod.go	92.18% <82.35%> (ø)
... and 5 more

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