Optimized Memory Usage for Constant Index Granularity in Large Workloads

Optimized memory usage for values of index granularity if granularity is constant for part. Added an ability to always select constant granularity for part (setting use_const_adaptive_granularity), which helps to ensure that it is always optimized in memory. It helps in large workloads (trillions of rows in shared storage) to avoid constantly growing memory usage by metadata (values of index granularity) of data parts. #71786 (Anton Popov).