Function isGuid

isGuid(guid): boolean
Determines whether the provided string is a GUID (Globally Unique Identifier).

This function checks if the provided string matches the regular expression for a GUID. A GUID is a unique reference number used as an identifier in computer systems. The GUID should be a 40 characters long hexadecimal string.
Parameters
- guid: unknown
  
  The string to be checked.
Returns boolean
true if the string is a GUID, otherwise false.
Example
```
// Returns: true
ix.api.is.isGuid("F001A9237C8C45502369F35D73CA3AE3AA166A0D");

// Returns: false
ix.api.is.isGuid("not-a-guid");
```