Make ComplexVectors support writing of ExtensionType

[xxlaykxx]

Added writer ExtensionWriter with 3 methods:

• write method for writing values from Extension holders;
• writeExtensionType method for writing values (arguments is Object because we don't know exact type);
• addExtensionTypeFactory method - because exact vector and value type are unknown, user should create their own extension type vector, writer for it and ExtensionTypeFactory where it should map vector and writer.

[github-actions]

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