Refactor schema impl - Githubissues

[x] Fix serde_arrow\src\internal\schema\test.rs
[x] Check that tests in serde_arrow\src\internal\schema\serde\test.rs still make sense
[x] Delete serde_arrow\src\internal\schema\deserialization.rs
[x] Add test to schema roundtrip (serialize - deserialize), in particular maps
[x] Include type_ids in UnionArray and UnionArrayView (and move checks for consecutive type ids into deserializer)
[x] Add Serialization Tests for TensorField, VariableShapeTensorField
[x] Update changelog

chmp / serde_arrow