Add Gro protocol adapter

[flabble-gro]

Initial version of adapter for gro-protocol. Using the previous projects approach, discussing in Discord channel with Garrett

[arman37]

It should count only locked tokens as TVL.

also the adapter throws error:

npm run test-tvl -- --project=gro                                                                                                                                         3250ms  Wed Dec 29 22:00:53 2021

> defipulse-adapters@1.0.0 test-tvl /Users/arman/Documents/Concourse/DeFi-Pulse-Adapters
> mocha v2/testing/test/*.js "--project=gro"



  Gro Protocol project adapter running & output format
    runs for a variety of points at different times
TypeError: sdk.util.sumSingleBalance is not a function
    at Object.tvl (/Users/arman/Documents/Concourse/DeFi-Pulse-Adapters/projects/gro/index.js:20:14)
    at process._tickCallback (internal/process/next_tick.js:68:7)
      1) returns valid tvl data at hour 0. Please go to the Leaderboard at https://test.defipulse.com and search for project: Gro Protocol-test-1640793807907 to validate the tvl!
      2) "after each" hook: save project adapter output for "returns valid tvl data at hour 0. Please go to the Leaderboard at https://test.defipulse.com and search for project: Gro Protocol-test-1640793807907 to validate the tvl!"


  0 passing (2s)
  2 failing