Display of numeric fields truncates trailing decimal 0s

Postico truncates trailing decimal 0s when displaying numeric fields. This is misleading when dealing with fixed-precision data (like money), and it causes values not to line up when there are multiple rows.

Appears to be the same issue as #205.

Thanks for taking a look!

```psql
SELECT 1.00::numeric, 15.010::numeric;
```

Expected (`psql`'s result):

```
numeric | numeric
---------+---------
1.00 | 15.010
```

Actual (Postico's result):

---

Postico version:
Version 1.4.2 (2845)

macOS version:
10.13.6

PostgreSQL version:
9.6.9

Start by reproducing the reported query in Postico and compare its numeric display with the shown psql output. Investigate how numeric fields are rendered, preserving trailing decimal zeros and column alignment; done means values such as 1.00 and 15.010 display with their original precision.

Written by the indexing model from the issue text.