This commit adds support for centralized metrics.
There are two providers as of now, and we haven't quite decided which
one to go for, so for the time being both are supported.
It also introduces a new endpoint InitializeApplication that replaces
OpenAccounts
* chore_:Don't rely on the master key when generating accounts under the bip 0044 path m/44'/60'/0'/0/0
* fix_: lint issue
* fix_: failed test TestBackendStartNodeConcurrently
- Moved some methods from Transactor to users of it to clean interface.
- Mocked Bridge interface and Transactor interface for tests
- Wrote unit tests for SendTransaction
Andrea Maria Piana
Ivan Belyakov
Igor Sirotin
frank