Ensure graphqlErrors always returns a value

[jerelmiller]

Fixes #1552

I have been unable to reproduce this myself since ApolloError.graphQLErrors is supposed to always be an array, but I've added a defensive fallback when serializing the error to ensure we always have a value.

[relativeci]

#1100 Bundle Size — 1.63MiB (~+0.01%).

59e3496(current) vs 2535670 main#1098(baseline)

Warning

Bundle contains 13 duplicate packages – View duplicate packages

Bundle metrics   2 changes 1 regression

	Current #1100	Baseline #1098
Initial JS	1.49MiB(~+0.01%)	1.49MiB
Initial CSS	0B	0B
Cache Invalidation	0.99%	0%
Chunks	5	5
Assets	157	157
Modules	1228	1228
Duplicate Modules	45	45
Duplicate Code	3.12%	3.12%
Packages	183	183
Duplicate Packages	10	10

Bundle size by type   1 change 1 regression

	Current #1100	Baseline #1098
JS	1.49MiB (~+0.01%)	1.49MiB
Other	100.55KiB	100.55KiB
IMG	35.85KiB	35.85KiB
HTML	857B	857B

Bundle analysis report Branch jerel/fix-some-bugs Project dashboard

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[pkg-pr-new]

npm i https://pkg.pr.new/apollographql/apollo-client-devtools@1606

npm i https://pkg.pr.new/apollographql/apollo-client-devtools/@apollo/client-devtools-vscode@1606

commit: 59e3496