Refactor reconcilers and controller manager construction logic

[chrisdoherty4]

These changes tidy up the tinker controller implementation in several ways:

1. Reduce the manager to a single NewManager function with the workflow controller pre-registerred.
2. Replace the full manager.Manager dependency in the Tink Server with a cluster.Cluster. Cluster objects are only really concerned with providing an API to retrieve a client and facilitate caching unlike the manager object that's concerned with all components related to controllers, webhooks, leader election and more. This makes the cluster object more appropriate for the Tink Server.
3. Colocate used indexes in the packages that consume them and remove unused indexes. Historically the unused indexes have been consumed by other Tinkerbell project; the projects can copy the indexes if still needed.
4. Rename workflow.Controller to workflow.Reconciler to be representative of the implementation. Controllers contain more than just reconciliation components.
5. Patch through metrics and prob endpoint configuration to the controller manager. The CLI flags are the common flags exposed from controllers: --metrics-bind-address, --health-probe-bind-address.

[codecov]

Codecov Report

Merging #674 (b9619ec) into main (5126bd0) will increase coverage by 1.03%.
The diff coverage is 42.59%.

❗ Current head b9619ec differs from pull request most recent head 9cba4cf. Consider uploading reports for the commit 9cba4cf to get more accurate results

@@            Coverage Diff             @@
##             main     #674      +/-   ##
==========================================
+ Coverage   48.26%   49.30%   +1.03%     
==========================================
  Files          18       18              
  Lines         951      860      -91     
==========================================
- Hits          459      424      -35     
+ Misses        484      428      -56     
  Partials        8        8              

Impacted Files	Coverage Δ
internal/server/kubernetes_api.go	0.00% <0.00%> (ø)
internal/server/kubernetes_api_workflow.go	30.15% <0.00%> (ø)
internal/workflow/reconciler.go	79.31% <57.14%> (ø)
internal/server/index.go	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

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