feat: support separate search indexes by version

[jbroma]

Summary

• added new search.versioned option to config
• removed redundant .filter by lang in LocalProvider
• fetch new index on version change (if enabled) in SearchPanel

Related Issue

#947

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

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[Timeless0911]

Thank you for your contribution~ We will review it ASAP

[sanyuan0704]

Thank you for your awesome work on this.