- to_char(datetime, format), format is specified
as in `strftime` function:
https://man.freebsd.org/cgi/man.cgi?query=strftime&sektion=3

Co-authored-by: EmirVildanov <reddog201030@gmail.com>

- support parameters in form of $n like in postgres
- parameters are numbered from 1
- can't use both tarantool (?) and pg-like ($n) params
in one query

- add support for queries that use
union all operator with global tables
- for the case when global table is
used against sharded table, the global
table is materialized only on single
storage, on all other storages the
global child of union all is not
materialized