Notify about illegal chars in title, and list them

[mat-m]

Is your feature request related to a problem? Please describe. I'm always frustrated when I try to add some characters in a Note's title, and that character silently disappear. E.g. I tried to add "R:" at the start of a note, and the colon disappeared silently. I needed to click rename once again, trying another character,and validate to check if it's allowed or not.

Describe the solution you'd like

1. Add the list of illegal characters in the Note Settings, so one could browse them before trying funny things
2. a. We should at least have a toaster saying a char has been removed for file compatibility reasons
3. b. A better user experience would be blocking the validation, with an inline message below the text input saying ":" is not allowed here