avro

AVRO-3133: Fix enum resolution to be consistent with Apache Avro specification and the schema compatibility checks (#1381)

* AVRO-3133: add schema compat test

add schema compatibility test to demonstrate that schema compatibility checks are consistent with the avro specification

* AVRO-3133: fix ENUM and FIXED resolvers

fix resolvers for ENUM and FIXED by having then compare unqualified name rather than qualified name

* remove duplicate test

* add missing test cases

* add test for writer with extra enum symbol and reader with default value

* reuse schemas from TestSchemas in TestResolvingGrammarGenerator

this required a change in visibility to two of the static members

* fix formatting