Add anchor dirty node check for text length less than 2 chars

[thegreatercurve]

Repro Steps:

1. Load Workplace on desktop
2. Navigate to system preferences >> keyboard >> text
3. Set "i" to replace with "I"
4. Navigate to playground
5. Type "i"+" "
6. Check if "i" is replaced to "I " or not.

Bug observed: Observe that, the text "i" is replaced to "I" instead of "I " when typed "i"+" ".

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated
lexical	✅ Ready (Inspect)	Visit Preview	💬 Add your feedback	Feb 7, 2023 at 0:21AM (UTC)
lexical-playground	✅ Ready (Inspect)	Visit Preview	💬 Add your feedback	Feb 7, 2023 at 0:21AM (UTC)

[github-actions]

size-limit report 📦

Path	Size	Loading time (3g)	Running time (snapdragon)	Total time
packages/lexical/dist/Lexical.js	30.69 KB (+0.01% 🔺)	614 ms (+0.01% 🔺)	165 ms (-61.68% 🔽)	778 ms
packages/lexical-rich-text/dist/LexicalRichText.js	36.19 KB (+0.01% 🔺)	724 ms (+0.01% 🔺)	253 ms (-18.3% 🔽)	977 ms
packages/lexical-plain-text/dist/LexicalPlainText.js	36.16 KB (+0.01% 🔺)	724 ms (+0.01% 🔺)	171 ms (+15.86% 🔺)	894 ms