refactor: Added util function jsonTypeRef for simplification of TypeR…

[npwork]

…ef creation (added to examples as well)

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Pull Request type

• Bugfix
• Feature
• Refactoring (no functional changes, no api changes)
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Changes in this PR

Before:

dgsQueryExecutor.executeAndExtractJsonPathAsObject<List<User>>(
    graphQLQueryRequest.serialize(),
    "data.users[*]",
    object: TypeRef<List<User>>() {}
)

After

dgsQueryExecutor.executeAndExtractJsonPathAsObject<List<User>>(
    graphQLQueryRequest.serialize(),
    "data.users[*]",
    jsonTypeRef()
)

Added util function jsonTypeRef (works the same as Jackson's jacksonTypeRef)

I know it's better suited to put it in com.jayway.jsonpath directly, but unfortunately it's Java project and they won't accept kotlin functions.

Anyway I think jsonTypeRef() is better than this object: TypeRef<List<User>>() {}

Describe the new behavior from this PR, and why it's needed
Issue #

Alternatives considered

Describe alternative implementation you have considered

I can see some usages inside graphql-dgs module. Maybe it makes sense to create graphql-dgs-common to reuse it around.

[berngp]

@npwork the changes look good but the linter failed the build .
Could you please run either make format or ./gradlew formatKotlin ?

[npwork]

You are right, will fix.

[berngp]

Thanks @npwork !