Post-fix to MDEV-30318 and MDEV-22570-related changes:
unified handling of wsrep_provider by code so that "none"
is interpreted as case-insensitive everywhere and that
work with an empty string is supported everywhere.

Integration with status reporter in wsrep-lib.

Status reporter reports changes in wsrep state and logged errors/
warnings to a json file which then can be read and interpreted by
an external monitoring tool.

Rationale: until the server is fully initialized it is unaccessible
by client and the only source of information is an error log which
is not machine-friendly. Since wsrep node can spend a very long time
in initialization phase (state transfer), it may be a very long time
that automatic tools can't easily monitor its liveness and progression.

New variable: wsrep_status_file specifies the output file name.
If not set, no file is created and no reporting is done.

Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

Changes to be committed:
	modified:   mysql-test/include/galera_variables_ok.inc
	modified:   mysql-test/include/galera_variables_ok_debug.inc
	modified:   mysql-test/suite/galera/r/galera_defaults.result
	deleted:    mysql-test/suite/galera/r/galera_var_wsrep_strict_ddl.result
	modified:   mysql-test/suite/galera/t/galera_defaults.test
	deleted:    mysql-test/suite/galera/t/galera_var_wsrep_strict_ddl.test
	modified:   mysql-test/suite/sys_vars/r/sysvars_wsrep.result
	modified:   mysql-test/suite/wsrep/r/variables.result
	modified:   mysql-test/suite/wsrep/r/variables_debug.result
	modified:   sql/sys_vars.cc
	modified:   sql/wsrep_mysqld.cc
	modified:   sql/wsrep_mysqld.h
	modified:   sql/wsrep_var.cc
	modified:   sql/wsrep_var.h

galera_var_wsrep_on_off : Add wait conditions to make sure DDL is
replicated before continuing.

wsrep.[variables|variables_debug] :  Remove unnecessary parts
and add check to correct number of variables or skip

galera_ssl_reload: Add version check and SSL checks.