Zabbix

A.F....... [ZBXNEXT-1675] changes:
- added LLD rule 'lifetime' and web scenario default defines;
- corrected web item history and trend default values;
- fixed sorting of action operations in case they contain macros;
- fixed saving trends value in configuration and displaying a trend value in item and item prototype list;
- removed unnecessary usage of "delay_flex";
- fixed clearing "lifetime" field for regular items;
- implemented resolving macros of time units and conversion to seconds;
- added older time unit without suffixes to import converter;
- added retrieval of time periods from TimePeriodsParser;
- increased the "maxlength" of item delay field to 1024 and "delay_flex" array to store unlimited amount of intervals;
- correct import unit test;
- fixed formatting in several places.