MDEV-18144: ANALYZE for statement support for PK filters

ANALYZE and ANALYZE FORMAT=JSON structures are changed in the way that they
show additional information when rowid filter is used:

- r_selectivity_pct - the observed filter selectivity
- r_buffer_size - the size of the rowid filter container buffer
- r_filling_time_ms - how long it took to fill rowid filter container

New class Rowid_filter_tracker was added. This class is needed to collect data
about how rowid filter is executed.

sql/sql_explain.h

@@ -624,6 +624,9 @@ public:
   /* Expected selectivity for the filter */
   double selectivity;
 
+  /* Tracker with the information about how rowid filter is executed */
+  Rowid_filter_tracker *tracker;
+
   void print_explain_json(Explain_query *query, Json_writer *writer,
                           bool is_analyze);