[Dynamic client] Better API for building arrays of input objects

[jmartisk]

Currently one has to do something like

new InputObject[] {
  inputObject(prop("x", "bla")),
  inputObject(prop("x", "bla2"))
}

which is not really fluent

An idea: perhaps this would help?

inputObjectArray(
  inputObject(prop("x", "bla")),
  inputObject(prop("x", "bla2"))
)

This inputObjectArray would be a static method of io.smallrye.graphql.client.core.InputObject and would return a InputObject[]