Add perserve-import-extensions

[AguacateContreras]

Add --preserve-import-extensions flag to Plasmic CLI

Problem

Currently, the Plasmic sync process automatically strips file extensions from import statements in generated code. For example, if a file has import Component from "./Component.jsx", the sync will transform it to import Component from "./Component".

This behavior is problematic for projects that:

• Use ESM modules with Node.js (which requires explicit file extensions)
• Have specific bundler configurations that expect explicit extensions
• Follow coding standards that mandate file extensions in imports
• Use TypeScript with moduleResolution: "node16" or "nodenext"

Solution

This PR adds a new --preserve-import-extensions flag that prevents the CLI from stripping file extensions during the sync process.

Usage

plasmic sync --preserve-import-extensions

When enabled, import statements will preserve their original file extensions:
- Before: import Component from "./Component"
- After: import Component from "./Component.jsx"

Implementation

The flag is implemented by:
1. Adding a new global setting preserveImportExtensions
2. Adding the CLI flag to the sync command options
3. Modifying the makeImportPath() function to conditionally skip extension stripping when the flag is set

The default behavior remains unchanged (extensions are stripped) to maintain backward compatibility.

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[github-actions]

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