[ocis][Sharing NG] Banned link password error message capitalization

## Describe the bug
The error message when trying to use a banned password for a public link should have proper capitalization.

## Steps to reproduce
1. Make sure you have a list of banned passwords for public links
2. Try creating a link with a banned password

## Expected behavior
The error message should be `Unfortunately, your password is commonly used. Please pick a harder-to-guess password for your safety`.

## Actual behavior
The error message is `unfortunately, your password is commonly used. please pick a harder-to-guess password for your safety`.