Cleanup around script_caller, fix tracking of scripts and ACL logging for RM_Call (#11770)

* Make it clear that current_client is the root client that was called by
  external connection
* add executing_client which is the client that runs the current command
  (can be a module or a script)
* Remove script_caller that was used for commands that have CLIENT_SCRIPT
  to get the client that called the script. in most cases, that's the current_client,
  and in others (when being called from a module), it could be an intermediate
  client when we actually want the original one used by the external connection.

bugfixes:
* RM_Call with C flag should log ACL errors with the requested user rather than
  the one used by the original client, this also solves a crash when RM_Call is used
  with C flag from a detached thread safe context.
* addACLLogEntry would have logged info about the script_caller, but in case the
  script was issued by a module command we actually want the current_client. the
  exception is when RM_Call is called from a timer event, in which case we don't
  have a current_client.

behavior changes:
* client side tracking for scripts now tracks the keys that are read by the script
  instead of the keys that are declared by the caller for EVAL

other changes:
* Log both current_client and executing_client in the crash log.
* remove prepareLuaClient and resetLuaClient, being dead code that was forgotten.
* remove scriptTimeSnapshot and snapshot_time and instead add cmd_time_snapshot
  that serves all commands and is reset only when execution nesting starts.
* remove code to propagate CLIENT_FORCE_REPL from the executed command
  to the script caller since scripts aren't propagated anyway these days and anyway
  this flag wouldn't have had an effect since CLIENT_PREVENT_PROP is added by scriptResetRun.
* fix a module GIL violation issue in afterSleep that was introduced in #10300 (unreleased)

src/debug.c

@@ -1846,14 +1846,13 @@ void logModulesInfo(void) {
 /* Log information about the "current" client, that is, the client that is
  * currently being served by Redis. May be NULL if Redis is not serving a
  * client right now. */
-void logCurrentClient(void) {
-    if (server.current_client == NULL) return;
+void logCurrentClient(client *cc, const char *title) {
+    if (cc == NULL) return;
 
-    client *cc = server.current_client;
     sds client;
     int j;
 
-    serverLogRaw(LL_WARNING|LL_RAW, "\n------ CURRENT CLIENT INFO ------\n");
+    serverLog(LL_WARNING|LL_RAW, "\n------ %s CLIENT INFO ------\n", title);
     client = catClientInfoString(sdsempty(),cc);
     serverLog(LL_WARNING|LL_RAW,"%s\n", client);
     sdsfree(client);
@@ -2112,7 +2111,8 @@ void printCrashReport(void) {
     logServerInfo();
 
     /* Log the current client */
-    logCurrentClient();
+    logCurrentClient(server.current_client, "CURRENT");
+    logCurrentClient(server.executing_client, "EXECUTING");
 
     /* Log modules info. Something we wanna do last since we fear it may crash. */
     logModulesInfo();