* Add version check mechanism to gRPC calls
* Use semver not semver/v3
* Give dev builds a special "infinite" version number (999.0.0-dev)
* Handle no metadata on grpc call correctly for version check
* Move versioncheck package to root pkg/ from pkg/api/ since it is shared by both pkg/api/ and pkg/client/
* Only show "no daemon version" warning once
* Append version headers to metadata, not overwrite...
* Unit tests on versioncheck logic
* Move SetHeader to the ServerStream in ServerStreamInterceptor
* Go modernizer nits: interface{} -> any
* Use more conventional gRPC header names for version/min-versions
* Add TODO notes on checkDaemonVersionInResponse and related code that can be removed eventually after transition to version checking client/daemons
* Use testify for testing assertions
* Add explanatory comments on MinCLIVersion and MinDaemonVersion
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Co-authored-by: Pasha Sviderski <me@psviderski.name>