modified the repetitive get method calls

[Tussle0410]

I've modified the DefaultClientRequestObservationConvention.class to reduce redundant calls to getCarrier() and getResponse() in ClientRequestObservationContext.

Previously, getCarrier() was called 8 times and getResponse() was called 3 times throughout the code.

I've modified the implementation to retrieve the ClientHttpRequest and ClientHttpResponse objects just once per method and then use these references for subsequent operations, making the code more efficient and easier to maintain.

	protected KeyValue clientName(ClientRequestObservationContext context) {
		if (context.getCarrier() != null && context.getCarrier().getURI().getHost() != null) {
			return KeyValue.of(LowCardinalityKeyNames.CLIENT_NAME, context.getCarrier().getURI().getHost());
		}
		return CLIENT_NAME_NONE;
	}

I've modified the existing code as shown below.

	protected KeyValue clientName(ClientRequestObservationContext context) {
		ClientHttpRequest request = getClientHttpRequest(context);
		if (request != null && request.getURI().getHost() != null) {
			return KeyValue.of(LowCardinalityKeyNames.CLIENT_NAME, request.getURI().getHost());
		}
		return CLIENT_NAME_NONE;
	}