Add Nx Code Generator for encapsulating ABP Schematics on NX repositories without 'angular.json' file

[mahmut-gundogdu]

Description

Nx can work withut angular json but our Abp Schematics won't. The pr constain nx generator work with angular schematics with or without angular.json.

Resolves #16515

Checklist

• I fully tested it as developer / designer and created unit / integration tests
• I documented it (or no need to document or I will create a separate documentation issue)

How to test it?

• Run backend app on nx project (like our abp repo)
• execute npx nx g @abp/generators:generate-proxy --module=identity --api-name=AbpIdentity --target=identity --project=identity --no-interactive --dry-run

[CLAassistant]

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