Various fixes and improvements

[NicoPennec]

Problem

• Inconsistent error handling between "create" a user and "create and send invitation" actions.
• When creating a bot, the generated token is not displayed in the field.
• Some users would like to have an x1.5 speed for the playlist player.
• Some outdated npm dependencies.

Solution

• Fix the error message when creating a person.
• Fix the value binding on the token field.
• Add the x1.5 speed to the playlist player.
• Bump npm dependencies.