feat: validation for Button Emoji and fixes

[biast12]

This pull request introduces a mix of styling updates, input behavior adjustments, and improved emoji handling in the frontend components. The most significant changes include refining emoji input behavior, and enhancing the handling of custom and Unicode emojis

• Non-custom emoji now only accepts 1 emoji (this will still fail as normal if an emoji is used that discord does not support) (you can still copy/paste emojis)
• Custom emoji now does not allow searching (adding your own text), automatically selects the first emoji from your server
• Both saves the option you had before switching between non-custom and custom emojis
• Also fixed some annoying styling when you're switching the "modes"

2025-05-24.01-14-09.mp4

^video to show how it works/looks

[BenHall-1]

tested locally, lgtm 🎉