Support for 256-bit Decimal Data Type in Various Functions and Protocols

Support 256-bit Decimal data type (more than 38 digits) in arraySum/Min/Max/Avg/Product, arrayCumSum/CumSumNonNegative, arrayDifference, array construction, IN operator, query parameters, groupArrayMovingSum, statistical functions, min/max/any/argMin/argMax, PostgreSQL wire protocol, MySQL table engine and function, sumMap, mapAdd, mapSubtract, arrayIntersect. Add support for big integers in arrayIntersect. Statistical aggregate functions involving moments (such as corr or various TTests) will use Float64 as their internal representation (they were using Decimal128 before this change, but it was pointless), and these functions can return nan instead of inf in case of infinite variance. Some functions were allowed on Decimal256 data types but returned Decimal128 in previous versions - now it is fixed. This closes #47569. This closes #44864. This closes #28335. #47594 (Alexey Milovidov).