Give more specific errors for verbatimModuleSyntax

[DanielRosenwasser]

Especially given that tsc --init initializes with VMS.

[Copilot]

Pull Request Overview

This PR improves error messages for the verbatimModuleSyntax TypeScript compiler option to provide more specific and actionable guidance to developers. The change replaces generic "ESM syntax is not allowed" messages with detailed explanations that include specific configuration suggestions.

Key Changes

• Replaces generic TS1286 error message with a new, more detailed TS1295 error message for verbatimModuleSyntax violations
• Adds conditional logic to provide different error messages based on file extensions (.cts/.cjs vs other files)
• Updates error message for module: preserve mode to be more descriptive

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 2 comments.

File	Description
src/compiler/diagnosticMessages.json	Adds new detailed error message (TS1295) and updates existing messages to be more specific
src/compiler/checker.ts	Implements logic to conditionally show different error messages based on file type and adds helper function
tests/baselines/reference/*.errors.txt	Updates test baselines to reflect the new, more detailed error messages

[Copilot]

The error message for .cts/.cjs files should provide guidance on how to resolve the issue, similar to the detailed message used for other file types. Currently it only states what's wrong without offering solutions.

Suggested change

	} else {
	if (fileExtensionIsOneOf(fileName, [Extension.Cts, Extension.Cjs])) {
	return Diagnostics.ECMAScript_imports_and_exports_cannot_be_written_in_a_CommonJS_file_under_verbatimModuleSyntax_Adjust_the_type_field_in_the_nearest_package_json_to_make_this_file_an_ECMAScript_module_or_adjust_your_verbatimModuleSyntax_module_and_moduleResolution_settings_in_TypeScript;
	} else {