ROVER-331 Add specific CompositionError handling

[jonathanrainer]

Fixes: #2421

It seems that in the move from old to new we got rid of some specific handling around composition errors. This has been re-added

Error From Rover v0.26.3

{"data":{"success":false},"error":{"code":"E029","details":{"build_errors":[{"code":"INVALID_GRAPHQL","message":"[object Object]","nodes":[{"end":null,"source":"@key(\"randomStuff\")\ntype Query {\n    field1: String!\n}","start":null,"subgraph":"fed-service-1"}],"omittedNodesCount":0,"type":"composition"}]},"message":"Encountered 1 build error while trying to build a supergraph."},"json_version":"1"} 

Error from Rover v0.27.2

{"json_version":"1","data":{"success":false},"error":{"message":"Encountered 1 build error while trying to build a supergraph.","code":null}}

Error from this PR

{"json_version":"1","data":{"success":false},"error":{"details":{"build_errors":[{"message":"[object Object]","code":"INVALID_GRAPHQL","type":"composition","nodes":[{"subgraph":"fed-service-1","source":"@key(\"randomStuff\")\ntype Query {\n    field1: String!\n}","start":null,"end":null}],"omittedNodesCount":0}]},"code":"E029","message":"Encountered 1 build error while trying to build a supergraph."}}

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Build ID: e103a40b4a2af358c137e3c7