Add support for overrideBootstrapCommand in AL2023

[TiberiuGC]

Description

Overriding bootstrapping in AL2023 is achieved by providing your own nodeConfig, which will be merged with the default one (created either by eksctl for self-managed nodes and customAMIs, or by EKS MNG, for eks-managed nodes based on native AMIs).

Please refer to userdocs -https://github.com/eksctl-io/eksctl/blob/main/userdocs/src/usage/node-bootstrapping.md

Closes #7852
Closes #8037
Closes #8043
Closes #7895

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the userdocs directory)
• Manually tested
• Made sure the title of the PR is a good description that can go into the release notes
• (Core team) Added labels for change area (e.g. area/nodegroup) and kind (e.g. kind/improvement)

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟

[a-hilaly]

👍

[a-hilaly]

discussed with @TiberiuGC regarding e2e tests. Pending more information on how we are testing these in the github actions

[a-hilaly]

Thank you @TiberiuGC !