Update transaction list to differentiate GraphQL requests

[ArjanSM]

:camera: Screenshots

:page_facing_up: Context

Issue #116 talks about the shortcoming of the initial approach of supporting GraphQL on Chucker.

This PR is an attempt support GraphQL on Chucker using the guidelines mentioned in Issue #116.

:pencil: Changes

1. Enable clients to set a graphQLEndpoint through the ChuckerInterceptor.Builder
2. Pass the graphQLEndpoint as an argument to the RequestProcessor.process(..) method
3. Add isGraphQLRequest property in the HttpTransaction entity & HttpTransactionTuple
4. Expose isGraphQLRequest via HttpTransactionTuple
5. Tests
6. Update Sample app to illustrate the effects of the change.

:paperclip: Related PR

PR#805 is also doing the same thing but does not handle GraphQL requests via HTTP GET methods. But this PR does not block any other PR.

:no_entry_sign: Breaking

1. ChuckerInterceptor now contains an additional parameter to represent a GraphQL path or url
2. RequestProcessor's process(..) method would accept the Graphql path passed by Interceptor.

:hammer_and_wrench: How to test

Test cases for RequestProcessor included in the PR.

:stopwatch: Next steps