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 a14d72c a9499ff 8c1cc36 c2a8d52 0edf690

Details for all reverted commits:

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

This reverts commit 0edf6907ae.

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

This reverts commit c2a8d52a13.

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

This reverts commit 8c1cc369d0.

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

This reverts commit a9499ff136.

Revert "sasl: Implement SASL authorisation identity via CURLOPT_SASL_AUTHZID"

This reverts commit a14d72ca2f.

src/tool_getparam.c

@@ -177,8 +177,7 @@ static const struct LongShort aliases[]= {
   {"$H", "mail-auth",                ARG_STRING},
   {"$I", "post303",                  ARG_BOOL},
   {"$J", "metalink",                 ARG_BOOL},
-  {"$6", "sasl-authzid",             ARG_STRING},
-  {"$K", "sasl-ir",                  ARG_BOOL },
+  {"$K", "sasl-ir",                  ARG_BOOL},
   {"$L", "test-event",               ARG_BOOL},
   {"$M", "unix-socket",              ARG_FILENAME},
   {"$N", "path-as-is",               ARG_BOOL},
@@ -1100,9 +1099,6 @@ ParameterError getparameter(const char *flag, /* f or -long-flag */
 #endif
           break;
         }
-      case '6': /* --sasl-authzid */
-        GetStr(&config->sasl_authzid, nextarg);
-        break;
       case 'K': /* --sasl-ir */
         config->sasl_ir = toggle;
         break;