Function hexEncode

hexEncode(value?): string
Converts an UTF-8 string into its hexadecimal representation.

This function takes a string as input and encodes it into UTF-8. It then converts each character into its hexadecimal equivalent, concatenates the results, and returns the final string in uppercase.
Parameters
- value: string = ""
  
  The string to be encoded. If not provided, an empty string will be used.
Returns string
The hexadecimal representation of the input string.
Example
```
// Encode a string into hexadecimal
const hexString = ix.api.text.hexEncode("fooBar");
console.log(hexString);  // Outputs: "666F6F426172"
```