Prevent Space, Lpad, Rpad functions from generating strings larger than 4G

[trueeyu]

Enhancement

Prevent Space, Lpad, Rpad functions from generating strings larger than 4G

[github-actions[bot]]

We have marked this issue as stale because it has been inactive for 6 months. If this issue is still relevant, removing the stale label or adding a comment will keep it active. Otherwise, we'll close it in 10 days to keep the issue queue tidy. Thank you for your contribution to StarRocks!