json_name and required field annotations not reflected in generated TypeScript output

[hishamank]

Describe the bug

When generating TypeScript code using this fork of protoc-gen-grpc-gateway-ts, I’ve noticed two issues:
1. Fields using the json_name option in proto definitions are not reflected in the generated TypeScript output.
2. Fields marked as required using both the -required comment and [(buf.validate.field).required = true]; are still generated as optional in TypeScript.

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To reproduce

1. json_name issue

Proto file example:

Generated TypeScript output:

Expected: The field name should match the json_name specified in the proto.

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2. Required field issue

Proto file example:

Generated TypeScript output:

Expected: Fields marked as required should be generated as non-optional.

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Expected behavior
• TypeScript interfaces should respect the json_name mapping from the proto.
• Fields marked as required should not be marked optional in the output.

[hishamank]

Implemented json_name handling here #38