..F.....S. [ZBX-21898] removed backslash escaping in string parameters of history functions
* commit '3e8577ddb03484d72a9d4d7c9d6f2da6aaec4613':
..F....... [ZBX-21898] added declaration types, fixed coding style, added some extra test cases
..F....... [ZBX-21898] fixed frontend phpunit tests
..F....... [ZBX-21898] removed unnecessary elseif
..F....... [ZBX-21898] fixed expression history function parser to accept backslashes without escaping
..F....... [ZBX-21898] reverted commit f2d771a28c1
..F....... [ZBX-21898] reverted commit d9e411dc586 and cab99d0d993 to match 6.0 version
........S. [ZBX-21898] applied changes from ZBX-22149 to release/6.4
