Add default role to workspace (#10444)

## Context
Adding a defaultRole to each workspace, this role will be automatically
added when a member joins a workspace via invite link or public link
(seeds work differently though).
Took the occasion to refactor a bit the frontend components, splitting
them in smaller components for more readability.

## Test
<img width="948" alt="Screenshot 2025-02-24 at 14 54 02"
src="https://github.com/user-attachments/assets/13ef1452-d3c9-4385-940c-2ced0f0b05ef"
/>

packages/twenty-front/src/modules/auth/states/currentWorkspaceState.ts

@@ -1,6 +1,6 @@
 import { createState } from '@ui/utilities/state/utils/createState';
 
-import { Workspace } from '~/generated/graphql';
+import { Role, Workspace } from '~/generated/graphql';
 
 export type CurrentWorkspace = Pick<
   Workspace,
@@ -23,7 +23,9 @@ export type CurrentWorkspace = Pick<
   | 'customDomain'
   | 'workspaceUrls'
   | 'metadataVersion'
->;
+> & {
+  defaultRole?: Omit<Role, 'workspaceMembers'> | null;
+};
 
 export const currentWorkspaceState = createState<CurrentWorkspace | null>({
   key: 'currentWorkspaceState',