✨ : stack (edition mode) - make specific form fields mandatory

[cdubuisson]

Is your feature request related to a problem? Please describe.
In the stack screen , some fields should be mandatory:

• name
• variables if specified (see ✨ : module - add an option to specify mandatory variable #72)

Describe the solution you'd like
Make the fields mandatory. If a mandatory field is empty, the input should be highlighted in red and the save should not be executed.
Check the fields in the view and in the controller.

Describe alternatives you've considered
N/A

Additional context
For the variables part, issue #72 should treated first.

[juwit]

see https://bootstrap-vue.js.org/docs/reference/validation