[BUG] The number component's preview panel does not show correct default value when user delete it

[lHilovsky]

Environment

• Formio.js version: 4.13.5
• Frontend framework: Angular
• Browser: Chrome

First issue

Steps to Reproduce

1. Write some number into default value
2. Delete digits one by one

Expected behavior

Default value should be empty

Observed behavior

First digit is still shown in preview panel

Example

https://user-images.githubusercontent.com/56341727/131491296-30e65888-7c01-40ee-b37f-ff79f26a5e2f.mp4

Second issue

Steps to Reproduce

1. Write some number into default value
2. Delete all digits at once

Expected behavior

Default value should be empty

Observed behavior

All digits are still shown in preview panel

Example

https://user-images.githubusercontent.com/56341727/131491704-ebce2eaa-0856-49a8-b03e-5147d633c1d3.mp4

Third issue

Steps to Reproduce

1. Write some number into default value
2. Delete digits by pressing the backspace button constantly

Expected behavior

Default value should be empty

Observed behavior

All digits except last are still shown in preview panel

Example

https://user-images.githubusercontent.com/56341727/131492059-9e5d8c28-e2c8-4a59-8d5e-777da381baf3.mp4