This adds the explorer and Pyth as optional components to improve
Tilt startup times, as originally suggested by Justin.
Defaults to true in CI.
Change-Id: Id9fffe5b11311baadc042815c0cc747de037554e
Ensure there's no core vs. token bridge ambiguity.
Breaking changes to the CLI:
* "guardiand bridge" CLI is now "guardiand node"
* --solanaBridgeAddress is now --solanaContract
* --bridgeKey is now --guardianKey
The Heartbeat proto message had one of its fields renamed from
BridgeAddress to ContractAddress, but this won't break the wire
format and the only consumer appears to be the CLI.
Change includes a "go mod tidy" - it insisted.
Change-Id: Id8b312827737f07f2d5f3944ebce469d946e7f51