UI: enforce limit in the UI and display number of characters

[benoit74]

For fields which have a limit on number of characters, it would be super helpful to:

• enforce the limit while editing the field (currently one has to save the recipe to have an error message)
• have a visual indicator of current number of characters (this is not my idea but one from @Popolechien in Clarify that Title should be max 30 characters long #777 and I can only agree)