Observers/Monitoring observers/Add individual observers #996

### Describe the issue

The "First Name" and "Last Name fields" in the Add Individual Observer form do not enforce validation and accept any characters

### Steps to reproduce

Go to the Observers from the main menu
Click to Add individual observers from the Monitoring observers list
Fill "First name" from the "Add a new observer"
Fill "Last name" from the "Add a new observer"
Fill "Email" from the "Add a new observer"
Fill "Phone number" from the "Add a new observer"

Expected behavior

The "First Name" and "Last name" fields should only allow alphanumeric characters (letters A–Z, a–z and numbers 0–9). Special characters (e.g., @, #, %, !, etc.) should be disallowed to ensure proper validation.

### Environment

Browser: Chrome 114
OS: EMUI 12.0.0
Device: Huawei Mate 10 Pro

### Additional context

This issue do not affect affects filtering and searching.