avro

AVRO-3468: Handle default values for logical types (#1622)

* AVRO-3468: Add handling of default values for logical types

This extends the resolver to handle default values for logical types
according to their base schema.

* AVRO-3468: Fix tests for conversion of default values to decimal logical type

Because of a possible bug in the handling of TestCaseData in NUnit,
the tests for the decimal logical type are separate from the tests
for other logical types.

* AVRO-3468: Add tests for decimal binary encoding

* AVRO-3468: Fix tests by parsing decimals culture-invariant

* AVRO-3468: Removes redundant using statement

* AVRO-3468: Add comment about CultureInfo to tests

Co-authored-by: l.heimberg <l.heimberg@cid.com>