Trace: provide performance statistics for DDL statements

[pavel-zotov]

It would be useful if trace setting print_perf = true could show performance statistics not only for DML but also for DDL statements.
Currently one may see performance data only for 'CREATE INDEX' statement (more accurately: performance of several system queries to RDB tables) .

This is example:

set bail on;
set names utf8;
shell del c:\temp\tmp4test.fdb 2>nul;
create database 'localhost:c:\temp\tmp4test.fdb' user 'SYSDBA' password 'masterkey';

set echo on;

create sequence g_common;
create collation name_coll for utf8 from unicode case insensitive;
create exception ex_context_var_not_found 'required context variable(s): @1 - not found or has invalid value';
create domain dm_idb as bigint;
create table test(id dm_idb not null, x dm_idb);
alter table test add constraint test_pk primary key(id);
create index test_x on test(x);
create view v_test as select * from test;

set term ^;
create trigger trg_test_bi before insert on test as
begin
    new.id = coalesce(new.id, gen_id(g_common,1));
end
^
create procedure sp_test(a_id dm_idb, a_x dm_idb) as
begin
    update test set x =:a_x where id = :a_id;
end
^

No any DDL will have performance 'blocks' in the trace here.
Every of them will be reflected as "0 records fetched / 0 ms".