..F....... [ZBX-8727] Implement CDecimalStringValidator class and test for it. Add T_ZBX_DBL_STR request parameter validation type and use it for item multiplier.

git-svn-id: svn://svn.zabbix.com/trunk@49305 f4e7fd02-d210-4e34-a1e0-d4093fb66cc2