⚡ (setVariable) Add "Environment name" value in Set variable block (#850)

Closes #848
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
### Summary by CodeRabbit

- New Feature: Added "Environment name" as a new value type in the
SetVariable function, allowing users to distinguish between 'web' and
'whatsapp' environments.
- Refactor: Simplified session state handling in `resumeWhatsAppFlow.ts`
for improved code clarity.
- Refactor: Updated `startWhatsAppSession.ts` to include an initial
session state with WhatsApp contact and expiry timeout, enhancing
session management.
- Bug Fix: Improved null handling in `executeSetVariable.ts` for
'Contact name' and 'Phone number', preventing potential issues with
falsy values.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/schemas/features/blocks/logic/setVariable.ts

@@ -5,6 +5,7 @@ import { LogicBlockType } from './enums'
 export const valueTypes = [
   'Custom',
   'Empty',
+  'Environment name',
   'User ID',
   'Now',
   'Today',