[Task]: Sort out validations for app name, page name and custom slug

[eco-monk]

Is there an existing issue for this?

• [X] I have searched the existing issues

SubTasks

Should these be different? App name - all characters are allowed now (shouldn’t be empty) Page name - alphanumeric and accented characters are allowed (shouldn’t be empty) Custom slug - alphanumeric and ’-” are allowed (can be empty)

Note: used in both entity explorer and settings pane