Pricing Upgrade Flow changes (#514)

* Pricing Upgrade Flow changes

* remove extra code

* Refactor subscription plan selection and billing management

* Polish the new pricing modal

---------

Co-authored-by: Julien Nahum <julien@nahum.net>

client/stores/subscription_modal.js

@@ -0,0 +1,31 @@
+import { defineStore } from 'pinia'
+
+const DEFAULT_MODAL_TITLE = 'Upgrade and take your forms to the next level'
+const DEFAULT_MODAL_DESCRIPTION = 'On the Free plan, you can try out all paid features only within the form editor. Upgrade your plan to gain full access to all features.'
+
+export const useSubscriptionModalStore = defineStore('subscription_modal', {
+  state: () => ({
+    show: false,
+    plan: null,
+    yearly: true,
+    modal_title: DEFAULT_MODAL_TITLE,
+    modal_description: DEFAULT_MODAL_DESCRIPTION
+  }),
+  actions: {
+    openModal (planName = undefined, isYearly = undefined) {
+      this.plan = (planName !== undefined) ? planName : null
+      this.yearly = (isYearly !== undefined) ? isYearly : true
+      this.show = true
+    },
+    setModalContent (title = null, description = null) {
+      this.modal_title = title || DEFAULT_MODAL_TITLE
+      this.modal_description = description || DEFAULT_MODAL_DESCRIPTION
+    },
+    closeModal () {
+      this.show = false
+      this.plan = null
+      this.modal_title = DEFAULT_MODAL_TITLE
+      this.modal_description = DEFAULT_MODAL_DESCRIPTION
+    }
+  }
+})