fix: Remove empty curly brackets while verbatimModuleSyntax is on onl…

[codenamenam]

…y if default import is used with named import

This PR fixes an issue where verbatimModuleSyntax would leave empty curly braces {} in the JavaScript output when an import statement has a default import and all of its named imports are type-only.

The transformer logic is updated to check for the presence of a default binding on the import code.

Fixes #62239

[jakebailey]

This PR needs tests.

[RyanCavanaugh]

@copilot add some tests

[codenamenam]

@jakebailey @RyanCavanaugh I added test case which verifies that empty braces are correctly removed from an import statement with a default binding and only type-only named bindings when verbatimModuleSyntax is enabled. If you have any questions, please let me know. Thank you!

[typescript-bot]

With 6.0 out as the final release vehicle for this codebase, we're closing all PRs that don't fit the merge criteria for post-6.0 patches. If you think this was a mistake and this PR fits the post-6.0 patch criteria, please post to the 6.0 iteration issue with details (specifically, which PR and which patch criteria it satisfies).

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