Fix for translation not working in graphql

[raivisdejus]

This fixes the following Magento issue magento/magento2#31351

Some additional info https://stackoverflow.com/questions/61770306/while-working-with-the-magento-2-graphql-it-seems-that-the-string-translation-do

[aleksandrsm]

is this actually necessary?
processRequest call in PersistedQuery is initiated by aroundDispatch method, so I assume that beforeDispatch plugin on the GraphQl controller would be enough

not 100% sure, perhaps an interaction with the around plugin makes it necessary, but please double check

[aleksandrsm]

see minor comments

& thanks for porting this fix to core PWA

[aleksandrsm]

personally, I'd put it in PersistedQuery module rather than CmsGraphQl, because it already has plugins on the GrapQL controller

[raivisdejus]

@aleksandrsm Please check my changes and comments

[aleksandrsm]

Approved, but I still don't see the reason for plugin on ScandiPWA\PersistedQuery\Plugin\PersistedQuery - please double check that

[raivisdejus]

processGraphqlRequest() is triggered in aroundPlugin and is to process cached queries. It is executed before the plugin on graphql controller
https://github.com/scandipwa/persisted-query/blob/master/src/Plugin/PersistedQuery.php#L227

So we need also this plugin to make translations work for all cases

[aleksandrsm]

Odd, as processRequest is triggered by aroundDispatch, which I thought would be executing after the beforeDispatch, which the new plugin adds on the base class. Not 100% sure on how the before-around interaction on plugins work, specially with multiple plugins involved.
I guess it doesn't work when the beforeDispatch is defined on the base class but not the PersistedQuery plugin.

Keep as is if it is necessary, and thanks for checking.