Add configuration file option to grpc plugin configuration tests.

[EinKrebs]

Requirement - what kind of business use case are you trying to solve?

I want to run integration tests on grpc plugin.

Problem - what in Jaeger blocks you from solving the requirement?

The plugin needs config file to be passed.

[pavolloffay]

@EinKrebs would you like to submit a PR and show how this can be used with the clickhouse plugin?

[pavolloffay]

There is already an exmaple of how to use the storage integration test with gprc-plugin

jaeger/plugin/storage/integration/grpc_test.go

Line 33 in f23484b

type GRPCStorageIntegrationTestSuite struct {