* Deprecate the Operation.operationName property in core/src/client

* Add some missing files

* Update the core exchanges

* Add a changeset

* Update the multipart-fetch exchange

* Update the persisted-fetch exchange

* Update exchanges and move getOperationName to utils

* Remove confusing destructuring

* Update the changeset

* Update the testing doc

* Update a reference to getOperationName

* Update a reference to makeOperation

* Make client.createOperationContext public

* Changes for PR feedback

* Update makeOperation and move addMetadata

The addMetadata utility was definitely kept in the wrong
place since it concerns operations.
`makeOperation` has been updated to fill out the context
if it isn't passed which may become convenient in a couple
of places, instead setting it to the `operation.context`.

* Update operation spreads to use `makeOperation`

* Fix additional operation mapping case in cacheExchange

* Update core docs and add callout to changeset

* Replace all remaining operation spreads with makeOperation
Co-authored-by: Phil Pluckthun <phil@kitten.sh>