Activity as standard object (#6219)

In this PR I layout the first steps to migrate Activity to a traditional
Standard objects

Since this is a big transition, I'd rather split it into several
deployments / PRs

<img width="1512" alt="image"
src="https://github.com/user-attachments/assets/012e2bbf-9d1b-4723-aaf6-269ef588b050">

---------

Co-authored-by: Charles Bochet <charles@twenty.com>
Co-authored-by: bosiraphael <71827178+bosiraphael@users.noreply.github.com>
Co-authored-by: Weiko <corentin@twenty.com>
Co-authored-by: Faisal-imtiyaz123 <142205282+Faisal-imtiyaz123@users.noreply.github.com>
Co-authored-by: Prateek Jain <prateekj1171998@gmail.com>

packages/twenty-front/src/modules/users/components/UserProviderEffect.tsx

@@ -54,6 +54,7 @@ export const UserProviderEffect = () => {
       setCurrentWorkspaceMember({
         ...workspaceMember,
         colorScheme: (workspaceMember.colorScheme as ColorScheme) ?? 'Light',
+        locale: workspaceMember.locale ?? 'en',
       });
 
       // TODO: factorize