Parametrized types do not allow spaces after "("
Following KSY raises error until space between `(` and `true` will be deleted:
```yaml
meta:
  id: type_references
seq:
  - id: field
    type: 'type::sub( true , 2 )'
types:
  type:
    types:
      sub:
        params:
          - id: par
            type: bool
          - id: par2
            type: u1
        seq: []
```
I think that is unnecessary restriction and it can be eliminated. The root of the problem is that parametric type parsing is partially done in manually, and partially using expression language. It is much easier to always parse the entire string as an expression, at the same time you can:
* allow spaces between `::`
* allow spaces in begin and at end of string
* allow spaces before `(`

Now corresponding PEG rule for type references is:
```
parseTypeRef = name ("::" name)* ("(" args _ ")")? EOS;
args = expr (_ "," _ expr)*;
...
```
But it would be:
```
parseTypeRef = _ name (_ "::" _ name)* _ ("(" _ args _ ")" _)? EOS;
```