Group "request add project version" needs field limit

User can send large emails via the additional information field

1. Sign in
2. Go to Groups
3. Select a group
4. Click the "...", then "Request to add project version" option
5. Select a project, then version
6. Paste a large amount of text of text to the Additional Information field
7. Click send

Actual:
Very large email received by admin/maintainer

Expected:
Field limit, 500 ~ 1000 characters