fix for \n in json selection arguments

[lennyburdette]

i dunno if this is the right fix

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• connectors-const - Connectors stress test that runs with a constant number of users
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• xlarge-request - Stress test with 10 MB request payload
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[benjamn]

Do we need to support literal \n sequences? Maybe inside string literals inside JSONSelection LitExpr syntax, but elsewhere they're just another kind of whitespace.

[lennyburdette]

string values can contain escapes: https://spec.graphql.org/draft/#sec-String-Value — i think these are intended to be equivalent:

"foo\nbar"

"""foo
bar"""

[lennyburdette]

JSONSelection on its own handles them just fine. the problem is that they get double-escaped when we read the string from the original source code in an attempt to preserve the original line/column for diagnostics