MDEV-27477 Remaining SUSE patches for 10.2+

This patch let's you specify not only user to use but also group that
MariaDB should use.

Original patch:
https://github.com/openSUSE/mysql-packaging/blob/master/patches/mysql-patches/mariadb-10.2.3-group.patch

Author:   Kristyna Streitova
Reviewer: monty@mariadb.org

scripts/mysql_install_db.sh

@@ -30,6 +30,7 @@ defaults=""
 defaults_group_suffix=""
 mysqld_opt=""
 user=""
+group=""
 silent_startup="--silent-startup"
 
 force=0
@@ -98,6 +99,11 @@ Usage: $0 [OPTIONS]
                        user.  You must be root to use this option.  By default
                        mysqld runs using your current login name and files and
                        directories that it creates will be owned by you.
+  --group=group_name   The login group to use for running mysqld.  Files and
+                       directories created by mysqld will be owned by this
+                       group. You must be root to use this option.  By default
+                       mysqld runs using your current group and files and
+                       directories that it creates will be owned by you.
   --upgrade-info       Store mysql_upgrade_info in the installed data directory.
 
 All other options are passed to the mysqld program
@@ -146,11 +152,11 @@ parse_arguments()
       --builddir=*) builddir=`parse_arg "$arg"` ;;
       --srcdir=*)  srcdir=`parse_arg "$arg"` ;;
       --ldata=*|--datadir=*|--data=*) ldata=`parse_arg "$arg"` ;;
-      --user=*)
         # Note that the user will be passed to mysqld so that it runs
         # as 'user' (crucial e.g. if log-bin=/some_other_path/
         # where a chown of datadir won't help)
-        user=`parse_arg "$arg"` ;;
+      --user=*) user=`parse_arg "$arg"` ;;
+      --group=*) group=`parse_arg "$arg"` ;;
       --skip-name-resolve) ip_only=1 ;;
       --verbose) verbose=1 ; silent_startup="" ;;
       --rpm) in_rpm=1 ;;
@@ -461,7 +467,12 @@ do
   fi
   if test -n "$user"
   then
-    chown $user "$dir"
+    if test -z "$group"
+    then
+      chown $user $dir
+    else
+      chown $user:$group $dir
+    fi
     if test $? -ne 0
     then
       echo "Cannot change ownership of the database directories to the '$user'"
@@ -476,6 +487,11 @@ then
   args="$args --user=$user"
 fi
 
+if test -n "$group"
+then
+  args="$args --group=$group"
+fi
+
 # When doing a "cross bootstrap" install, no reference to the current
 # host should be added to the system tables.  So we filter out any
 # lines which contain the current host name.