✨ (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/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 = (