Refactor: Saas Connector template

[ErKiran]

Used a types for node and jest, included jest config for test

Added getOAuth2AccessToken() mock method to compile the test cases

Description

What is the intent of this change and why is it being made?

This PR updates the default SailPoint SaaS connector template to compile and run tests cleanly in a local TypeScript/Jest development environment.

Changes made:

• Added Node and Jest type support so TypeScript can recognize node, describe, it, and expect.
• Added Jest configuration for running TypeScript test files through ts-jest.
• Added the required getOAuth2AccessToken() mock method to the test Context object so the generated test cases compile against the current SailPoint Connector SDK interface.

How Has This Been Tested?

What testing have you done to verify this change?

I verified the change by compiling the Go binary, using it to generate a new SaaS connector project, and then running the generated connector test suite with npm test.

The test confirmed that the generated connector template now compiles successfully, the TypeScript/Jest setup works correctly, and the default connector unit tests pass after adding the required getOAuth2AccessToken() mock method to the SailPoint SDK Context object.

The successful npm test output has been attached as evidence.

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