feat(esptool): merge_bin CMake target (IDFGH-12541)

[nebkat]

No description provided.

[github-actions]

	Warnings
⚠️	The Pull Request description is empty. Please provide a detailed description.

👋 Hello nebkat, we appreciate your contribution to this project!

---

📘 Please review the project's Contributions Guide for key guidelines on code, documentation, testing, and more.

---

🖊️ Please also make sure you have read and signed the Contributor License Agreement for this project.

---

Click to see more instructions ...

This automated output is generated by the PR linter DangerJS, which checks if your Pull Request meets the project's requirements and helps you fix potential issues.

DangerJS is triggered with each push event to a Pull Request and modify the contents of this comment.

Please consider the following:
- Danger mainly focuses on the PR structure and formatting and can't understand the meaning behind your code or changes.
- Danger is not a substitute for human code reviews; it's still important to request a code review from your colleagues.
- Resolve all warnings (⚠️ ) before requesting a review from human reviewers - they will appreciate it.
- To manually retry these Danger checks, please navigate to the Actions tab and re-run last Danger workflow.

Review and merge process you can expect ...

We do welcome contributions in the form of bug reports, feature requests and pull requests via this public GitHub repository.

This GitHub project is public mirror of our internal git repository

1. An internal issue has been created for the PR, we assign it to the relevant engineer.
2. They review the PR and either approve it or ask you for changes or clarifications.
3. Once the GitHub PR is approved, we synchronize it into our internal git repository.
4. In the internal git repository we do the final review, collect approvals from core owners and make sure all the automated tests are passing.
- At this point we may do some adjustments to the proposed change, or extend it by adding tests or documentation.
5. If the change is approved and passes the tests it is merged into the default branch.
5. On next sync from the internal git repository merged change will appear in this public GitHub repository.

Generated by 🚫 dangerJS against e96da70

[Honza0297]

Hello @nebkat and thank you for your contribution!
Can I ask you why did you choose the CMake approach (instead of writing it in a Python layer?) Is there any use case this solution is better for you etc.?
The reason why I am asking is that currently, very similar MR is in the internal review. The difference is that the internal solution is implemented on the Python level, which is generally more convenient if there is no explicit need to have a CMake target.
Thank you for your answers!

[nebkat]

@Honza0297 I haven't spent enough time around idf.py internals and the CMake system so I might not fully understand, but:

My main requirement is to be able to generate the merged binary without having to specify @flash_args and chip type manually, this will make it easier for both CI and developer using idf.py - I'm guessing both solutions achieve this.

It does feel like something that fits in to the CMake system since it is generating binaries, and this would allow it to be used from IDE (I am successfully using CMake in CLion). I don't have any such use case right now but it would also allow for other targets to depend on the merged binary file, maybe for some customized release system.

[Honza0297]

I understand your main requirement - both approaches (CMake and Python) will solve it.
We are trying to have these "aliases" for (not only) esptool commands in one place in Python code and make CMake targets only if necessary.
If there is no specific use case in the moment, we would stay with the current approach of implementing it in Python (specifically, merge-bin will be in the master branch in several days).
We will close this PR for now, but we may reopen it if you or somebody else would need the target.
Thank you for understanding.

[dobairoland]

We will add a cmake target as well.