Avoid user to trigger a creation process twice

[benjaminpochat]

In case a creation/modification process is long, the validating button should be disabled (with a spinner inviting the user to wait), and a snack bar might say when the process is finished.

Without that, if the process is long, the user will trigger the creation/modification process twice (thinking "it didn't work !").

[benjaminpochat]

Done for order creation dialog.
To be done for other post services :

• save delivery order modifications by breeder
• save product by breeder
• save product template by breeder
• create account by customer
• update password
• save slaughter by breeder

[benjaminpochat]

Done for account creation by customer.
To be done for other post services :

• save delivery order modifications by breeder
• save product by breeder
• save product template by breeder
• update password
• save slaughter by breeder