testing: Move crypto to drivers and open_memstream to libc

[xiaoxiang781216]

Summary

follow the dissusion from:
#2931

Impact

testing folder relayout

Testing

ci

[nuttxpr]

[Experimental Bot, please feedback here]

No, this PR description does not adequately meet the NuttX requirements. Here's why and how to fix it:

Missing Information:

• Summary: While linking the discussion is helpful, the summary needs to stand alone. Explain why the testing folder relayout is necessary. What problem does it solve? What are the benefits? How does the relayout work (what's the new structure)?
• Impact: Saying "testing folder relayout" isn't sufficient. Be specific. Does this impact users? Will they need to change their workflow or scripts? Does it change the build process (e.g., new dependencies, different build targets)? Does it affect any specific architectures, boards, or drivers? Does documentation need updating? Address all the impact points with NO/YES and explanations where necessary. Even if the answer is NO, state it explicitly.
• Testing: "ci" is not enough. Which CI runs are relevant? Provide links to successful CI runs. What specific tests were run locally? What are the "before" and "after" results? Just saying "ci" doesn't demonstrate that the change works as intended. Provide concrete evidence. You need to fill in the "Testing logs before change" and "Testing logs after change" sections with actual logs or output, even if it's just demonstrating that a build now succeeds where it previously failed. State your build host details (OS, CPU, Compiler). State your target details (Architecture, board, configuration).

Example of a Better Description:

## Summary

This PR restructures the testing folder to improve organization and maintainability.  The current structure is difficult to navigate and makes it hard to locate specific tests. This change groups tests by functionality, creating subfolders for unit tests, integration tests, and system tests.  This will make it easier for developers to find and run relevant tests and contribute new tests in the future.  This addresses discussion in https://github.com/apache/nuttx-apps/pull/2931.

## Impact

* Is new feature added? NO
* Is existing feature changed? YES - The organization of the testing folder is changed.
* Impact on user (will user need to adapt to change)? YES - Users relying on the previous folder structure for scripting or manual testing will need to update their paths.
* Impact on build (will build process change)? NO
* Impact on hardware (will arch(s) / board(s) / driver(s) change)? NO
* Impact on documentation (is update required / provided)? YES - The testing documentation needs to be updated to reflect the new folder structure. A PR to update the documentation will be submitted separately.
* Impact on security (any sort of implications)? NO
* Impact on compatibility (backward/forward/interoperability)?  YES - Existing test scripts that rely on the old folder structure may break. Guidance on migration will be provided in the updated documentation.
* Anything else to consider?  None.

## Testing

I confirm that changes are verified on local setup and works as intended:
* Build Host(s): Linux (Ubuntu 20.04), x86_64, GCC 9.4.0
* Target(s): sim:qemu-x86_64

Testing logs before change:

Previous structure made it difficult to find the test_example.py

find . -name test_example.py
./tests/misc/test_example.py # Hard to predict location

Testing logs after change:

New structure allows easy location

find . -name test_example.py
./tests/unit/example/test_example.py # Clear and predictable

CI runs:

* [Link to successful CI run 1]
* [Link to successful CI run 2]

By providing this level of detail, reviewers can quickly understand the changes, their impact, and the verification performed, leading to a faster and smoother review process.

[cederom]

Thank you @xiaoxiang781216 :-)

There is some CI error, I have restarted, go ahead when ready :-)

[cederom]

CI build fixed, thank you @xiaoxiang781216, merging :-)