RuntimeHooks for Addon-Management implementation

[sbueringer]

Implementation umbrella issue for #6374
As the proposal (#6418) has been merged, we can start with the implementation now.

Done:

• Add API types (🌱 Add lifecycle hook types #6537 @ykakarap @killianmuldoon )
• Implement lifecycle hooks without tracking (@ykakarap) ✨ RuntimeSDK: BeforeClusterCreate, BeforeClusterUpgrade implementation #6608
• Implement lifecycle hooks with tracking (except delete) (@ykakarap) ✨ Implements AfterControlPlaneInitialized, AfterControlPlaneUpgrade and AfterClusterUpgrade hooks #6629
• Verify that up/down conversion of embedded Cluster resources would work (✨ [POC] Bump RuntimeSDK sbueringer/cluster-api#50)
• Implement e2e test
  • PR initial test: (🌱 Initial e2e test for Runtime SDK lifecycle hook #6664 @killianmuldoon)
  • Follow-up: test blocking behavior (🌱 Add blocking end-to-end tests for lifecycle hooks #6761 @killianmuldoon)
• BeforeClusterDelete (✨ Implements BeforeClusterDelete hook #6644 @ykakarap)
• book: documentation (📖 Runtime SDK: extend documentation & update proposals accordingly #6756 @sbueringer)
• Make sure that we test the BeforeClusterDelete hook in e2e (🌱 Add BeforeClusterDelete to runtimeSDK e2e tests #6805 @killianmuldoon)

TODO before v1.2.0 release:

-

Follow-up:

• Sequential upgrades (or not) and what does it mean for lifecycle hooks: Prevent upgrades of managed topologies while previous upgrade is not yet completed #6651

/kind feature
/area runtime-sdk