✨ (theme) Custom font option (#1268)

Closes #1249

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
- Introduced components for customizing fonts, including Google and
custom font options.
- Enhanced theme customization by simplifying theme objects and adding
new font customization options.
- Implemented dynamic font injection for web pages based on
user-selected font configurations.

- **Bug Fixes**
- Fixed a condition in theme template card rendering to correctly check
avatar enablement.
- Corrected font property handling across various components to support
both string and object types.

- **Refactor**
	- Updated option properties in RadioButtons component to be readonly.
- Simplified logic for setting CSS variables for fonts, including checks
for font types and existence.

- **Documentation**
- Added constants and schemas for supporting new font types in theme
customization.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/deprecated/bot-engine/src/components/TypebotViewer.tsx

@@ -13,7 +13,6 @@ import {
 } from '@typebot.io/schemas'
 import { Log } from '@typebot.io/prisma'
 import { LiteBadge } from './LiteBadge'
-import { isNotEmpty } from '@typebot.io/lib'
 import { BackgroundType } from '@typebot.io/schemas/features/typebot/theme/constants'
 import { env } from '@typebot.io/env'
 
@@ -74,7 +73,7 @@ export const TypebotViewer = ({
       </style>
       <style>{typebot.theme?.customCss}</style>
       <style>{importantStyles}</style>
-      {isNotEmpty(typebot?.theme?.general?.font) && (
+      {typebot?.theme?.general?.font && (
         <style
           dangerouslySetInnerHTML={{
             __html: `@import url('https://fonts.googleapis.com/css2?family=${

packages/deprecated/bot-engine/src/features/theme/utils/setCssVariablesValue.ts

@@ -50,7 +50,8 @@ const setGeneralTheme = (
 ) => {
   const { background, font } = generalTheme
   if (background) setTypebotBackground
-  if (font) documentStyle.setProperty(cssVariableNames.general.fontFamily, font)
+  if (font && typeof font === 'string')
+    documentStyle.setProperty(cssVariableNames.general.fontFamily, font)
 }
 
 const setChatTheme = (