Bug: default cases in Date and Boolean params

[JuanMartinP]

In pr #102 we observed problems when using the default value in params with type Date and Boolean. When sending the params there's no problem but when taking the value for the param from the default key in the params object we get errors (possible problems with format).
In the commit 2957896 of the same pr we add a workaround for the tests.

[GregorioBlazquez]

The root cause was that default parameter values were not validated when creating a DA.
Runtime query params were validated/coerced, but DA defaults could be persisted without compatibility checks, which later caused failures for types like Boolean and DateTime.