Run tests with with -race flag and fix race conditions

[CluEleSsUK]

While replacing circle CI with github actions, @AnomalRoil suggested running the go test runner with the race flag to check for race conditions. This identified some race conditions in DKG code that require investigation and remediating.

During prior investigation, a data access races were identified in the StatusMatrix struct implementation. Adding some generic RW locking worked fine on my local machine and the tests (including race condition testing) passed successfully.
On the github actions runner however the TestProtoFull test in proto_test.go appeared to suffer deadlock (albeit the go runtime did not detect this). Note: this deadlock does not happen without the -lock flag

Some attempts I tried to remedy this:

• updating go to 1.18
• adding test flag GO111MODULE=on
• adding test flag GODEBUG=cgocheck=2 (see testing: go 1.17 regression: deadlock in test suite golang/go#48402)
• modifying the resCh in TestProtoFull buffer size to 0 and 2 (see testing: go 1.17 regression: deadlock in test suite golang/go#48402)
• running tests without make
• implementations of StatusMatrixwith RWLock and vanilla Lock
• a variety of timeouts up to 30mins
• running macos-latest and ubuntu-latest github runners

[AnomalRoil]

I think this was fixed in #34 in the end.