Revert all SASL authzid (new feature) commits

- Revert all commits related to the SASL authzid feature since the next
  release will be a patch release, 7.65.1.

Prior to this change CURLOPT_SASL_AUTHZID  / --sasl-authzid was destined
for the next release, assuming it would be a feature release 7.66.0.
However instead the next release will be a patch release, 7.65.1 and
will not contain any new features.

After the patch release after the reverted commits can be restored by
using cherry-pick:

git cherry-pick a14d72ca a9499ff1 8c1cc369 c2a8d52a 0edf6907

Details for all reverted commits:

Revert "os400: take care of CURLOPT_SASL_AUTHZID in curl_easy_setopt_ccsid()."

This reverts commit 0edf6907.

Revert "tests: Fix the line endings for the SASL alt-auth tests"

This reverts commit c2a8d52a.

Revert "examples: Added SASL PLAIN authorisation identity (authzid) examples"

This reverts commit 8c1cc369.

Revert "curl: --sasl-authzid added to support CURLOPT_SASL_AUTHZID from the tool"

This reverts commit a9499ff1.

Revert "sasl: Implement SASL authorisation identity via CURLOPT_SASL_AUTHZID"

This reverts commit a14d72ca.