Add IP validation on the AltTester Popup

## Description

Context:
- Since we do not have an IP validation on the green popup there is a situation in WebGl builds where if there is an invalid IP used there is an error triggered in the browser and the build gets stuck (see screenshot)


## Mocks

## Additional info

Locate the AltTester Popup, specifically the green popup used in WebGL builds, and trace how its IP value is accepted. Reproduce the invalid-IP case described in the issue and observe the browser error and blocked build. Done means invalid IP input is detected in the popup and no longer triggers that WebGL failure; the issue names no files or tests.

Written by the indexing model from the issue text.