Update Espressif examples for Managed Component publish

[gojimmypi]

Although it is already closed, this PR addresses #697 and updates the published Espressif wolfSSH Managed Component.

See the wolfSSL scripts for publishing details. I'll reference this PR when I submit the updates there.

There was an interim update of wolfSSL that had a test but not a fix for interleaved HW/SW that could under certain circumstances be problematic for both SSH and SRP. This was fixed in wolfSSL/wolfssl#7535 and wolfSSL/wolfssl#7505.

Once updated after the 5.7.0 wolfSSL release, the wolfSSL Managed Component needed to be updated as well.

There's a new wolfSSL 5.7.1 preview release, published to wolfssl/versions/5.7.1-preview2d. Note this is not the default version that appears at the wolfSSL Managed Components Home Page, since it is not a formal release. (wolfSSL 5.7.1 is not a wolfSSL version as of today).

I would have called it something like 5.7.0+Rev1 but I could not get that syntax to work with the Espressif site, even though it is vali according to https://semver.org/.

Various issues addressed here:

• Updated the CMakeFiles.txt to be a bit more robust and consistent with other similar files elsewhere.
• Fixes the Espressif example echoserver that had a bad parameter void* args = {0}; instead of func_args args = {0};
• Minor README.md file updates

The known-working, post-release Managed Components are:

wolfSSH: https://components.espressif.com/components/wolfssl/wolfssh/versions/1.4.17-preview1m5

and

wolfSSL: https://components.espressif.com/components/wolfssl/wolfssl/versions/5.7.1-preview2d?language=en

I expect the next product release versions will be a bit more graceful.