[sergeyfast]

Problem

Since #62 (the fix for #56), dbtest wraps the int32/int64 cast around the
whole assignment:

int64(in.TgUserID = gofakeit.IntRange(1, 10))

This is not valid Go, so in v0.6.1 mfd-generator dbtest fails to format
the output and aborts on any model with a non-nullable column mapped to
int32 or int64 (e.g. int8/bigint).

Fix

Cast the fake value first, then assign: toInt64().assign(col) instead of
assign(col).toInt64(), in both ByNameAndType and ByType:

in.TgUserID = int64(gofakeit.IntRange(1, 10))

Tests

• Add TestFakeFiller_IntCast: int32/int64 columns via ByType and
  ByNameAndType produce the expected statement, and it parses as Go.
  Fails on master, passes with the fix.
• The newsportal testdata maps all integer columns to int except one
  nullable *int64, which is not faked, so the golden files did not catch
  this.