MyBatis Collection don't need ofType

I really don't think ‘ofType’ is needed in Collection,We can cache the first ParameterizedType to replace it

Comment From: harawata

Please add a test case.

Comment From: moonService

@harawata if you think cache the first ParameterizedType is unnecessary，I offer you another pr to choose，You can take a look at pr#1773 if you have time