Support schema evolution when using non-default constructors

[nicodeslandes]

Support new fields in Schema when using non-default constructors

Description

This PR addresses #358 by making the record deserializer more tolerant when selecting constructors, which is critical for supporting schema evolution in immutable records.

The Problem

Previously, BinaryRecordDeserializerBuilder (and the JSON equivalent) required a constructor to match the Avro schema fields exactly. This meant that adding a new field to a schema (typically a backward-compatible change) would break deserialization for existing C# record types that hadn't yet been updated to include the new field. The deserializer would fail to find a matching constructor and throw an exception.
This is rather inconsistent with the way we handle new properties for classes that expose public properties and a default constructor

Example:

Old schema:

{
    "type": "record", 
    "name": "Person", 
    "fields": [
        {"name": "name", "type": "string"}
    ]
}

C# record / class:

public record PersonRecord(string Name);
public class PersonClass
{
    public required string Name {get; init; }
}

All good so far, we can happilly serialize/deserialize to/from either form of DTO

But when a new, backward-compatible field is added to the schema::

{
    "type": "record", 
    "name": "Person", 
    "fields": [
        {"name": "name", "type": "string"}, 
        {"name": "age", "type": "int", "default": 20}
    ]
}

PersonClass is still usable; we can generate both serializer and deserializer for it
But attempting to generate a deserializer for PersonRecord produces the following exception:

var deserializer = new BinaryDeserializerBuilder().BuildDelegate<PersonRecord>(newSchema);

💀💀💀 Exception:
Type 'TestProject1.PartialConstructorMatchingTests+PersonRecord' does not have a default constructor (Parameter 'type')
   at System.Linq.Expressions.Expression.New(Type type)
   at Chr.Avro.Serialization.BinaryRecordDeserializerBuilderCase.BuildExpression(Type type, Schema schema, BinaryDeserializerBuilderContext context)
   at Chr.Avro.Serialization.BinaryDeserializerBuilder.BuildExpression(Type type, Schema schema, BinaryDeserializerBuilderContext context)
   at Chr.Avro.Serialization.BinaryDeserializerBuilder.BuildDelegateExpression[T](Schema schema, BinaryDeserializerBuilderContext context)
   at Chr.Avro.Serialization.BinaryDeserializerBuilder.BuildDelegate[T](Schema schema, BinaryDeserializerBuilderContext context)

The Fix

The deserializer logic has been updated to select the "best match" constructor rather than requiring an exact match:

1. It identifies constructors where all parameters can be satisfied (either by a matching schema field or a default value).
2. It allows extra schema fields to be present. These extra fields are:
   • Mapped to writable properties if a match exists (Hybrid Construction).
   • Ignored if no match exists.

This behavior allows a client with an older version of a record (missing a new field) to successfully deserialize data from a newer schema version, ignoring the unknown fields.

Additional Improvements

• Hybrid Construction: This change naturally supports mixing constructor initialization with property setters.
• Default Values: Constructor parameters with default values are now correctly utilized if the corresponding field is missing from the schema.

Verification

New tests in PartialConstructorMatchTests verify:

• Schema Evolution: Deserializing a schema with extra fields into a record that doesn't define them (fields are ignored).
• Hybrid Construction: Populating some fields via constructor and others via properties.
• Default Values: Using default parameter values when schema fields are missing.

[nicodeslandes]

I just rebased over the latest changes from main. This is now ready to be merged (at least as far as git is concerned :-) )