feat: regex pattern set for Score (for override only) field

[MAAngamarca]

Description

This PR includes a fix to prevent Reflected Cross-Site Scripting on Score (for override only) field. This attack is visible in the following image:

Changes

• Changes input type to number to filter only numbers.
• Adds a sanitize function to remove extra characters on the score variable.

How to test:

In devstack:

• Get the devstack up and running from this branch
• On a Blank Common Problem and with a staff user, click on STAFF DEBUG INFO

• In Score (for override only) field, paste this code: <script>alert('yes')</script>, click on Override Score button and no alert should be displayed.