Remove `removeDirective` exchange to be agnostic to GQL client

[IzumiSy]

Currently, fabrix internally depends on urql, but we have a plan to make it pluggable by #123

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Background

Currently, fabrix has two special client-side directives (fabrixForm and fabrixView) that are not expected to be sent to the GraphQL server.

So in fabrix, we have a custom urql exchange to delete them before sending requests, but it works only with urql.

This is the ticket to remove the exchange (removeDirective) and do the same thing in the layer of GraphQL visitor instead.

https://github.com/fabrix-framework/fabrix/blob/main/packages/fabrix/src/exchanges/removeDirectives.ts