Enforce that if request/correlation id provided, it must be a UUID otherwise generate new

Issue
Currently, any value is accepted.

Expectation
Only UUIDs should be accepted.

The could be implemented with a new kwarg on the Plugins so this isn't a breaking change for any users who currently accept request values that are not UUIDs.

Relevant source code

starlette-context/starlette_context/plugins/correlation_id.py

Lines 14 to 22 in 79aa8ff

    
           async def extract_value_from_header_by_key( 
        
               self, request: Request 
        
           ) -> Optional[str]: 
        
               await super( 
        
                   CorrelationIdPlugin, self 
        
               ).extract_value_from_header_by_key(request) 
        
               if self.value is None: 
        
                   self.value = uuid.uuid4().hex 
        
               return self.value

Happy to submit a PR if needed.

Makes sense.

Feel free to open a PR or I'll do that myself over the weekend.

	async def extract_value_from_header_by_key(
	self, request: Request
	) -> Optional[str]:
	await super(
	CorrelationIdPlugin, self
	).extract_value_from_header_by_key(request)
	if self.value is None:
	self.value = uuid.uuid4().hex
	return self.value