Clarify advice to apply for jasmin-login first when applying for other services

See HS#59528. Currently there's a banner saying "in order to apply for a group workspace you need to have `jasmin-login` first. Can we either:
* make it clearer that this is general advice, rather than a state preventing this user from proceeding with a GWS application, or
* display the warning only if the user **doesn't** currently hold `jasmin-login`