Add complex response components

[tweakch]

Description

• Added generated Unit Tests for Services
• Added default query parameters
• Added Models for complex property types.
• Added utility extensions for AmountCollection and Amount to sum by asset.
• Added docs
• Applied OpenApiSpec 0.1.28
• Fix file encodings
• Updated the NET5.0 samples
• Updated the README
• Updated samples
• Updated Method Signatures => 0.3.0

Related issues

• Generate Services and Models (incl Unit Tests) from OpenApi Specs #28
• Add Unity sample package #37
• Add Utility Extensions #51
• Generate Model Components #52

[tweakch]

a85c58f WIP

[soyfrien]

@mmahut @vladimirvolek

Would you please look at this, or consider giving @tweakch the necessary permissions to move the project along.

[mmahut]

@tweakch all good to merge this?

[slowbackspace]

@mmahut looks like this PR is superseded by #55 since it includes last commit from this PR. I'll close it.