Add lang option to proxy preview, etc.

[shawnbot]

A couple of updates to the proxy preview API:

1. You can now pass lang=(es|zh|fil) in the query string to set the form language. (The rest of the page appears in English, but we can address that separately.)
2. We now support formioSFDSVersion in the query string as a replacement for the more ambiguous version parameter.

3. The form preview details box now includes the versions of both formiojs and formio-sfds (this library):

   

Also, the browser export now includes the version from package.json, which you can access in a browser via FormioSFDS.version.

[vercel[bot]]

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🔍 Inspect: https://vercel.com/sfds/formio-sfds/jv82bko1v
✅ Preview: https://formio-sfds-git-preview-lang.sfds.vercel.app

[github-actions[bot]]

Size Change: +19 B (0%)

Total Size: 91.9 kB

Filename	Size	Change
dist/formio-sfds.standalone.js	68.2 kB	+19 B (0%)

ℹ️ View Unchanged

| Filename | Size | Change | | |:--- |:---:|:---:|:---:| | `dist/common.css` | 332 B | 0 B | | | `dist/examples.js` | 3.51 kB | 0 B | | | `dist/examples/example.js` | 508 B | 0 B | | | `dist/formio-sfds.css` | 14 kB | 0 B | | | `dist/portal.js` | 5.36 kB | 0 B | |

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