Study description: remove characters limits

[elisabettai]

Long Story Short
I try to insert this string as a study description: "Pre-operative workflow for spinal cord injury rehabilitation with an analysis and planning system"

And the I get a very cryptic error

This is because there's a limit of 100 characters. This limit is not needed anymore, because the description goes in a scrollable container (just confirmed this with @odeimaiz)

Solutions

1. Preferred: remove the characters limit
2. Mitigation: show a clear message to the user. The backend actually gives a pretty informative message:
   

Actual behaviour
The user doesn't know what's going on

Steps to reproduce

1. Go to osparc.io (or any other deployment)
2. Click on a study card and put a long string in the description

[elisabettai]

Assigning all the backenders, as I imagine this is an easy bug to fix. If not, please let me know and we discuss (at the next planning?) @GitHK, @pcrespov @sanderegg, sorry for the spam. 😊