Increase server limit on invitations

[SimoneZaza]

Description

As a user inviting people, I do not want to get scary errors. For posts and other places in the platform, we have a character limit on the server that is much higher than the one on the client, to make sure that people always reach the client limit first (since formatting is not counted on the client, but is on the server). We need the same for invitations. See conversation here: https://teams.microsoft.com/l/message/19:[email protected]/1739262208280?tenantId=d7cd650f-6063-4276-8982-07e68da3c582&groupId=58cb15e6-a259-413c-9ee3-448cf9eb3574&parentMessageId=1739262208280&teamName=Product&channelName=3.%20Support%20from%20Product%20or%20Design%20%F0%9F%8E%A8&createdTime=1739262208280

Acceptance criteria

• Server character limit for invitations to be at least twice the size of the client limit (client limit is 2048)
• …

Additional Context

Areas that will be affected

To be added during the refinement