[BUG]: Dynamic update model issue

[chinalu]

Describe the bug
Same as #12773, when field type is Decimal or Float。

If old value in database is 1.0, then use RawValue to update this field, will reproduce this bug. Because of following logic

case Column::TYPE_DECIMAL:
case Column::TYPE_FLOAT:
    let changed = floatval(snapshotValue) !== floatval(value);
    break;

Because:

floatval(new \Phalcon\Db\RawValue("f+1")) === float(1)

So to reproduce the issue, should be

1. snapshotValue is 1,
2. use RawValue to update this field
3. the field type is DECIMAL or FLOAT

[niden]

Resolved in #15781