bug: Decimal256 display is not correct

[b41sh]

Decimal256 display padding zero is missed.

root@localhost:18000/default> select 0.0000000000000000000000000000000001234;

SELECT
  0.0000000000000000000000000000000001234

┌─────────────────────────────────────────┐
│ 0.0000000000000000000000000000000001234 │
│             Decimal(37, 37)             │
├─────────────────────────────────────────┤
│ 0.0000000000000000000000000000000001234 │
└─────────────────────────────────────────┘
1 row read in 0.020 sec. Processed 1 row, 1 B (51.04 row/s, 51 B/s)

root@localhost:18000/default> select 0.0000000000000000000000000000000000001234;

SELECT
  0.0000000000000000000000000000000000001234

┌────────────────────────────────────────────┐
│ 0.0000000000000000000000000000000000001234 │
│               Decimal(40, 40)              │
├────────────────────────────────────────────┤
│ 0.1234                                     │
└────────────────────────────────────────────┘
1 row read in 0.019 sec. Processed 1 row, 1 B (51.46 row/s, 51 B/s)