upperCase 
Converts a string to upper case.
Upper case is the naming convention in which each word is written in uppercase and separated by an space ( ) character. For example, UPPER CASE.
Signature 
typescript
function upperCase(str: string): string;Parameters 
- str(- string): The string that is to be changed to upper case.
Returns 
(string) The converted string to upper case.
Examples 
typescript
import { upperCase } from 'es-toolkit/string';
upperCase('camelCase'); // returns 'CAMEL CASE'
upperCase('some whitespace'); // returns 'SOME WHITESPACE'
upperCase('hyphen-text'); // returns 'HYPHEN TEXT'
upperCase('HTTPRequest'); // returns 'HTTP REQUEST'
