DEICH-6281 - Fixed validation so that it is instantly fired as the valid flag is updated using svelte reactive declarations.
Note, that EditNumber is used only one place with required set to false, so testing that component in validation sense is not possible by testers. Did a local testing, works ok.
EditNumber`s functionality was improved. The previous version allowed typing of non-numeric characters in the input fields, and there was no error reported at all. In this case the value was set to undefined, but still looked strange, that the create/save button was enabled. This new version fixes this issue. The implementation was somewhat cumbersome since I had to listen to onkeyup event, and check the input validity through input.validity.valid.
Closes DEICH-6281