Enable emoji search by pasting emoji characters

[apurv3170]

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• I have read the README and Contributor Guidelines
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Contributor checklist:

• My contribution is not related to translations.
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• My changes are rebased on the latest main branch
• A pnpm run ready run passes successfully (more about tests here)
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Description:

Allow searching for emojis in the emoji picker using the emoji itself on the Desktop version similar to what's already been implemented in Android/iOS counterpart.

What changed:

• ts/components/fun/useFunEmojiSearch.dom.tsx: 4 lines added to the search logic layer, so emoji character search works automatically across all emoji pickers in the app.

Implementation	Screenshots
Before
After

Testing:

• Manually tested on Windows 11 (OS build 26200.8037)
• Typed as well as pasted an emoji character into the reaction picker search box: both return correct results
• Verified existing text-based search still works normally
• No new automated tests added as this is a search input handling change

References:

• This mirrors the same feature already implemented on Signal-Android as well as Signal-iOS.

• Idea of this PR was highlighted by the community's feature request