avro

[AVRO-3433][rust] Adding in Resolve Fixes and Tests (#1582)

* AVRO-3433: Rust: The canonical form should preserve schema references

Do not resolve Schema::Ref when printing as JSON.
The Java SDK complains that a type is redefined if it is not a Ref the
second time

Signed-off-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>

* AVRO-3433: Use Name as a key for parsed/resolving/input schemata

This is needed to have the fullname (namespace + '.' + name) for lookups

Signed-off-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>

* AVRO-3433: adding in resolve fixes and tests

* AVRO-3433: Fix formatting and clippy errors

Signed-off-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>

* AVRO-3433: Give better names to the new test cases

Signed-off-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>

* AVRO-3433: Collect all Union schemata in schemas_by_name to be able to resolve Schema::Ref's

Signed-off-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>

* AVRO-3433: Add schema name validation

Signed-off-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>

* AVRO-3433: Use the regex to capture the namespace and name

Signed-off-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>

* AVRO-3433: Register all union's schemata in schemas_by_name, so that Schema::Ref's can be resolved

Signed-off-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>

* AVRO-3433: Add in encoding tests

Co-authored-by: Martin Tzvetanov Grigorov <mgrigorov@apache.org>
Co-authored-by: Martin Grigorov <martin-g@users.noreply.github.com>