feat: add teams (#848)

## Description

Add support for teams which will allow users to collaborate on
documents.

Teams features allows users to:

- Create, manage and transfer teams
- Manage team members
- Manage team emails
- Manage a shared team inbox and documents

These changes do NOT include the following, which are planned for a
future release:

- Team templates
- Team API
- Search menu integration

## Testing Performed

- Added E2E tests for general team management
- Added E2E tests to validate document counts

## Checklist

- [X] I have tested these changes locally and they work as expected.
- [X] I have added/updated tests that prove the effectiveness of these
changes.
- [ ] I have updated the documentation to reflect these changes, if
applicable.
- [X] I have followed the project's coding style guidelines.

packages/lib/server-only/team/create-team-billing-portal.ts

@@ -0,0 +1,47 @@
+import { getPortalSession } from '@documenso/ee/server-only/stripe/get-portal-session';
+import { IS_BILLING_ENABLED } from '@documenso/lib/constants/app';
+import { TEAM_MEMBER_ROLE_PERMISSIONS_MAP } from '@documenso/lib/constants/teams';
+import { prisma } from '@documenso/prisma';
+
+export type CreateTeamBillingPortalOptions = {
+  userId: number;
+  teamId: number;
+};
+
+export const createTeamBillingPortal = async ({
+  userId,
+  teamId,
+}: CreateTeamBillingPortalOptions) => {
+  if (!IS_BILLING_ENABLED) {
+    throw new Error('Billing is not enabled');
+  }
+
+  const team = await prisma.team.findFirstOrThrow({
+    where: {
+      id: teamId,
+      members: {
+        some: {
+          userId,
+          role: {
+            in: TEAM_MEMBER_ROLE_PERMISSIONS_MAP['MANAGE_BILLING'],
+          },
+        },
+      },
+    },
+    include: {
+      subscription: true,
+    },
+  });
+
+  if (!team.subscription) {
+    throw new Error('Team has no subscription');
+  }
+
+  if (!team.customerId) {
+    throw new Error('Team has no customerId');
+  }
+
+  return getPortalSession({
+    customerId: team.customerId,
+  });
+};