[api-extractor] fix namespace support

[adventure-yunfei]

Summary

api-extractor generates invalid dts results for some namespace declaration cases. e.g.

• [api-extractor] Re-exported import * namespaces produce malformed .d.ts rollups (with bundledPackages) #4807
• [api-extractor] Namespace/Module Declaration has {}; at the end #3127
• invalid dts results in current repo:
  • https://github.com/microsoft/rushstack/blob/main/build-tests/api-extractor-scenarios/etc/apiItemKinds/rollup.d.ts#L31
  • https://github.com/microsoft/rushstack/blob/main/build-tests/api-extractor-scenarios/etc/apiItemKinds/rollup.d.ts#L39

Details

Code changes summary:

• Analyzing phase: analyze "export { A as B }" node (which should be referenced by namespace)

• Emitting phase:

  • fix export/default/declare modifier only for root declarations.
  • when renaming Identifier node, fix a special case for "export { A }"

• Fixed [api-extractor] Re-exported import * namespaces produce malformed .d.ts rollups (with bundledPackages) #4807

• Fixed [api-extractor] Namespace/Module Declaration has {}; at the end #3127

• Fix unexpected export of actual un-exported declaration:
  input:

  export namespace PartalExportedNS {
    interface UnexportedClass { }
    export interface ExportedInterface {
      prop: UnexportedClass;
    }
  }

  expected output:

  export declare namespace PartalExportedNS {
    interface UnexportedClass {
    }
    export interface ExportedInterface {
      prop: UnexportedClass;
    }
    export { };
  }
  export { }

  actual output:

  export declare namespace PartalExportedNS {
    // This should not be exported
    export interface UnexportedClass {
    }
    export interface ExportedInterface {
      prop: UnexportedClass;
    }
    { };
  }
  export { }

How it was tested

Added a new namespaceDeclaration test case, and verified other test results.

Impacted documentation

[octogonz]

@adventure-yunfei Thanks for this fix!

Overall it looks good to me. I will merge it after testing.