Trim passwords

[elsirion]

Handle errors when submitting invalid passwords. Idk if that's being done rn. fedimint/fedimint#6253

[kleysc]

Hi @elsirion,

In PR fedimint/fedimint#6253, backend logic was added to remove leading and trailing whitespace from passwords. I propose replicating this in the frontend for consistency and to provide immediate feedback to users.

Should we also include validations for password strength (e.g., minimum 12 characters, at least one uppercase letter, one lowercase letter, one number, and one special character) with clear error messages to guide users?